2.13.25

More than a token photo

When asked to name scientists, students mention the likes of Charles Darwin, Albert Einstein, and Isaac Newton. And when asked to draw a scientist, students almost always draw a white man holding a test tube and wearing a lab coat. Professor Robin Costello from the University at Buffalo tells us more about a new study that parsed the effects of including visual depictions and humanizing information about scientists featured in undergraduate biology course materials.

This post was originally released by The Royal Society, here.

How students think of scientists reflects the false narrative that only certain types of people can be scientists – specifically white men with brilliant minds.

One powerful tool to combat this false narrative is to feature relatable, contemporary scientists whose identities do not match the dominant stereotype of a scientist featured in course materials. To highlight counter-stereotypical scientists, instructors can implement course materials that include photographs of scientists in their lecture slide decks. Or instructors can highlight humanizing information about scientists in their course materials. Sharing information such as the barriers scientists have faced or how they overcame obstacles in STEM may help students relate to scientists and envision their own STEM careers.

In our latest study, we parsed the effects of including visual depictions and humanizing information about scientists featured in undergraduate biology course materials with a large-scale research study. Over several academic terms and 36 undergraduate institutions in the United States, we distributed three versions of short quantitative activities (Data Nuggets) that varied in their level of information about the featured scientists (from including only their names and pronouns to full Project Biodiversify scientist profiles).

Data from over 3,700 students revealed that including humanizing information about scientists improves student engagement with quantitative biology activities. Photos of the scientists alone were not enough to improve student engagement. Instead, when provided information about the scientists’ life experiences, students found the activities more interesting, more relevant to their future careers, and put more effort into the activities. Our data suggests this pattern was driven by increased relatability of the featured scientists. 

Diagram of the three different treatments

While these results applied to all students, the strongest impacts were evident among students who shared excluded identities with the featured scientists.Our findings underscore the importance of providing students with examples of relatable scientists in STEM courses, rather than simply adding photos to increase representation. By highlighting humanizing information about scientists, instructors can both increase student engagement in their courses and improve equity in STEM.

We recommend several evidence-based resources to use in biology courses, including the Data Nuggets and Project Biodiversify materials studied here (together, DataVersify), as well as Scientist Spotlights, BioGrapI, and the Story Collider Podcast.

2.10.25

Science Doesn’t Stop in the Winter!

When the days grow shorter and the landscape is blanketed in snow, it might seem like nature has gone dormant. Trees stand bare, ponds freeze over, and many animals disappear from sight. But winter is a critical time for many species. Researchers brave the cold to study how organisms survive and even thrive in winter’s harsh conditions.

For many species, winter isn’t an obstacle—it’s a necessity. Some organisms have evolved incredible adaptations to endure the cold. Insects use snow as an insulating blanket and even plants rely on winter conditions, with some seeds requiring a cold period before they can sprout.

Rosemary Martin in the lab with tanks of dragonfly larvae.

But winter isn’t what it used to be; Climate change is altering seasonal patterns, leading to shorter, warmer winters. These changes disrupt the delicate balance that many species depend on. Snow cover is disappearing earlier, and fluctuating temperatures cause unpredictable freeze-thaw cycles, which can be harmful to plants and animals alike.

Postdoctoral researcher associate Rosemary Martin (Rosie) studies how cold temperatures affect the development of organisms, particularly dragonfly larvae. These larvae spend their early lives underwater before emerging as winged adults, and rather than hibernating in winter, they remain active. Understanding how temperatures shape their development is crucial, especially as climate change alters seasonal temperature patterns.

To investigate this, Rosie and her colleagues conduct lab experiments with six species of dragonflies. They expose them to different pre-winter temperatures before placing them in bio chambers at 4°C—mimicking the temperature of water beneath the ice. By measuring metabolic rates and analyzing fat and protein levels, they aim to uncover how different pre-winter conditions influence their health and survival. If larvae grow faster or slower due to higher pre-winter temperatures, it could impact the entire food web, from the predators that rely on dragonflies to the insects they eat.

“They actually stay active through the winter,” Rosie explains. “You can imagine how having built up resources—and still burning through them during the winter—affects their body condition in the spring. That’s what we’re trying to understand.”

Dragonfly larvae (photo credit: Rosemary Martin)

Despite the cold temperatures, Rosie notes that “this is the part that I enjoy the most. […] Part of the reason I got into winter ecology is because I wanted an excuse to get outside into the field all year round.” Winter ecology does come with its unique challenges though. It is often understudied as it doesn’t line up with the usual academic schedule. “There’s also the danger of working on ice,” Rosie mentioned, “especially during the shoulder seasons when it’s less stable. And, of course, a lot of people just don’t think about winter as a biologically active season. […] But in these mid-latitude to high-latitude environments it is obviously a really impactful environmental filter.”

One surprising fact Rosie often shares is that many people don’t realize dragonflies have an aquatic stage at all. “First, I have to explain that, and then I get to the fact that they’re active through the winter—which surprises not just the general public but even some ecologists.”

A Data Nugget on Rosie’s research will be published shortly! 

Getting Students Involved in Winter Science

For educators or students interested in exploring winter science, Rosie offers creative ideas. “If you have access to a refrigerator—and don’t mind keeping live insects in there—it can serve as a great proxy for an aquatic winter environment at 4°C,” she suggests. A mini bio chamber with LED lights and a timer can simulate winter conditions.

For those exploring the outdoors, Rosie recommends digging under the snow to examine leaf litter insects. “Try warming them up and see how long it takes for them to resume activity—that can give you insights into their overwintering strategies!” Other ideas include observing animal tracks, studying winter-active birds, and comparing how different types of trees handle the cold.

Dragonfly adult (photo credit: Rosemary Martin)

Bringing Winter Science to Your Classroom With Data Nuggets

Winter offers countless opportunities to engage students in real-world science. Data Nuggets provides resources to explore seasonal changes, including lessons on:

These lessons use real data collected by scientists, allowing students to analyze patterns and draw their own conclusions. By bringing winter science into the classroom, you can help students see that research doesn’t stop when the temperature drops—it simply takes on a new form.

So, this winter, bundle up and explore the science happening all around you! Whether it’s tracking animal footprints in the snow, investigating how ice forms, or analyzing real-world data, there’s no shortage of discoveries waiting to be made.

External Links: 

Life under the Ice

Dragonfly larvae

1.20.25

Microbes facing tough times

Jennifer sampling soil before the shelters were set up. Here you can see the control (left) and carbon addition (right) plots.

The activities are as follows:

As the climate changes, Michigan is expected to experience more drought. Droughts are periods of low rainfall when water becomes limiting to organisms. This is a challenge for our agricultural food system. Farmers in Michigan will be planting crops into conditions that make it harder for corn, soybean, and wheat to grow and survive.

Scientists are looking into how crop interactions with other organisms may help. Microbes are microscopic organisms that live in soils everywhere. Some microbes can help crops get through time times. These beneficial microbes are called mutualists. They give plants nutrients and water in exchange for carbon from the plant. Microbes use the carbon they get from plants as food. If plants are stressed and don’t have any carbon to give, microbes get carbon from dead plant material in the soil.

Jennifer is a biologist studying the role of microbes in agriculture. She has always been interested in a career that would help people. As a student, Jennifer thought she would have a career in politics. Along the way, she learned that a career in science is a great way to study questions that may lead to solutions for the challenges we are facing today. Jennifer was drawn to the Kellogg Biological Station, where she joined a team of scientists studying the impacts of climate change and drought on agriculture.

Jennifer and other scientists set out to test ways that we can give mutualists in the soil a boost. She thought, perhaps if we were to give microbes more food, they would be less stressed during a drought and would be able to help out crops growing in these stressful conditions.

To test this idea, Jennifer needed to test how well microbes were doing under different carbon and drought conditions. First, she set up treatments in soybean fields to manipulate the amount of carbon in the soil. She set up control plots where she left the soil alone. She also set up carbon treatment plots where dead plant litter was added to the soil to increase the carbon available to microbes.

Next, Jennifer manipulated the availability of water in her plots to test the microbes under stress. To do this, she set up her plots under shelters that kept out rain. The shelters had sprinklers, which were automated to add specific amounts of water to the plots. This design allowed Jennifer to control the watering schedule for each plot. One shelter treatment was a control, where water was added to the plots every week. This is similar to the schedules of local farmers who add water through irrigation. The other shelter treatment was drought, where plots received no water for six weeks. This experiment was replicated 4 times, meaning there were 4 shelters on the control watering schedule and 4 shelters that were under drought conditions.

A view of one of the shelters used in Jennifer’s experiment.

Finally, Jennifer had to measure how the microbes were doing in each treatment. She did this by measuring their enzyme activity. Enzyme activity is a measure of how active the microbes are. The higher the enzyme activity, the happier the microbes are. To measure this, Jennifer collected soil samples from each plot throughout the growing season and took them to the lab to measure enzyme levels in the soil samples. These enzymes are made by microbes when they are active. She then calculated the mean of all her samples for each treatment combination.

Jennifer predicted two things. First, if drought is harmful to microbes, then she would expect to see lower enzyme activity in the drought treatment compared to the irrigated treatment. Second, if adding carbon to the soil is a way to help microbes overcome the challenge of drought, she expected higher enzyme activity in the plots with plant litter added compared to the control treatment. Both of these taken together would indicate that drought is stressful for microbes, but we can help them out by adding resources like plant litter to soils.

Featured scientist: Jennifer Jones (she/her) from the Kellogg Biological Station Long Term Ecological Research Site. Written with Melissa Frost and Liz Schultheis.

Flesch–Kincaid Reading Grade Level = 8.2

Additional teacher resources related to this Data Nugget:

To introduce this Data Nuggets activity, students can watch a talk by Jennifer when she made a classroom visit to share her background and research interests. This video is a great way to introduce students to scientist role models and learn more about what a career in science looks like, as well as get an introduction to the themes in the research.

There is also a video of Jennifer and her scientist colleague, Grant Falvo, out in the field talking about their research under the rainout shelters.

For more information about the rainout shelter experiment, students can watch this short video featuring Jennifer Jones and another scientist on the team, Grant Falvo:

These data are part of the Kellogg Biological Station Long Term Ecological Research Program (KBS LTER). To learn more about the KBS LTER, visit their website.

1.9.25

Do you feel the urban heat?

Attaching a heat sensor to a street sign in Miami to monitor urban temperatures.

The activities are as follows:

Record-breaking temperatures climb higher every year, and Florida is no exception. In Florida, the impact of climate change is felt mostly during the hurricane season. Storms are becoming more violent and show up earlier in the season. These extreme temperatures and weather events affect living organisms of all types, including humans. Outdoor workers, the elderly, and all people who lack adequate housing are susceptible to temperature changes in the environment.

Heat sensor ready to be put out into the city.

Irvin teaches science at a high school in Miami, Florida. On his way to work, he listens to a local radio station to catch up on the news. One day the radio hosts were talking about an increase in homelessness in Miami and other cities. They also brought up the record heat that the U.S. was experiencing and how this may affect those without homes. This conversation on the radio made Irvin think. He reflected on the impact that such high heat could have on individuals who sleep without air conditioning.

This inspired Irvin to learn more about what could be done to mitigate the impact of climate change in his city. Irvin joined a program that invites teachers to work in scientists’ labs in the summer to gain research experience. Irvin was matched with Tiffany, a scientist interested in how urban heat can change based on structures like concrete buildings, urban dwellings, and unshaded places. Irvin took this opportunity to explore how high temperatures in Miami affect the daily lives of people living there. First, Irvin started looking into how temperatures are reported in Miami. He learned that there was just a single sensor stationed at the nearby airport. The heat and humidity readings from this one sensor are used by local officials to alert the entire city about dangerous heat levels. Alerts are issued when the heat index reaches 108 degrees Fahrenheit or higher. Heat index is a value that represents how the body feels temperature when humidity is factored in. With these alerts, people can take action by spending less time outside.

Teachers visiting the mangroves in Miami on a record heat day.

Irvin realized that no matter how reliable the sensor at the airport is, there is likely a larger range of temperatures within the city. He wanted to know whether the temperatures at the airport were similar to the heat felt at places where people spend time outside.

Tiffany’s research team had already started to collect temperature data in urban places where they hadn’t been recorded before. Since 2018, her lab placed hundreds of small heat sensors around the city. The sensors go out for 3 months and then the team collects them, records their data, and places them back out into new areas of the city.

Irvin wanted to compare areas that varied in coverage from the sun. He focused on sites where people gathered and spent long periods of time outside – bus stops. Some of the sites he chose had shade from trees, some had a roof providing partial sun cover, and other sites were totally exposed with no shade. Irvin took photos of each bus stop and used them to classify all sites as either full coverage, partial coverage, or no coverage. He used data from the airport as a control comparison to his bus stop sites.

Featured scientists: Irvin E. Arce (he/him) and Tiffany Troxler (she/her) from Florida International University

Flesch–Kincaid Reading Grade Level = 9.6

12.20.24

Does the heat turn caterpillars into cannibals?

Kale in the lab setting up an experiment with fall armyworms.

The activities are as follows:

Around the world, temperatures are rising from climate change. This is a hot topic for scientists because warmer temperatures could make diseases spread a lot faster. Many diseases spread by the foods we eat. With warmer temperatures, metabolisms increase, and organisms need to eat more food to survive. This increases the risk of eating something that will get them sick.

When Kale started graduate school, they joined a lab that studies how climate change affects the spread of disease in fall armyworms, a type of caterpillar. Fall armyworms are an agricultural pest known for destroying corn, soybeans, and other crops worldwide. In the summer, they move into fields and rapidly chow down on crops. It’s often reported by farmers that it seems as though fall armyworms can remove all the leaves from a cornfield overnight! Believe it or not, their huge appetite leads them to another food source – they will even turn into cannibals and eat each other!

Once Kale started graduate school, they became interested in how cannibalism can increase disease spread in warmer temperatures. Fall armyworms can get infected with a special type of virus called a baculovirus. Baculoviruses are a group of viruses that infect insects, especially caterpillars. They are highly specialized, meaning that each baculovirus usually only infects one species.

A fall armyworm that has been liquified due to a baculovirus infection.

If a fall armyworm eats a fellow fall armyworm that is infected, it can be deadly. In fact, the disease causes their body to completely liquify into a puddle of pure virus! This baculovirus is so effective that farmers even use it to help control infestations in their fields. Since this specific baculovirus only infects fall armyworms, it is safe to use on crops without worrying about effects on humans or other living things.

To study how cannibalism can affect disease spread, Kale designed a set of experiments. They thought that when temperatures are higher, the larvae’s metabolism would increase and make them hungrier caterpillars. Increased appetite could then lead to more cannibalism. As a result, more larvae would be eating others that are infected, further spreading the deadly baculovirus.

To test these ideas, Kale set up small Petri dishes and placed one big fall armyworm in each dish as the focus of each trial. Kale added a piece of insect food and a smaller fall armyworm to each dish. This way, the larger caterpillars had the option of eating the insect food, cannibalizing its smaller friend, or munching on both.

To see if temperature had an impact, Kale set up three treatments at low, medium (ideal), and high temperatures. They assigned 40 Petri dishes to each temperature. To test changes in disease transmission, half of the smaller caterpillars were infected with baculovirus, and half remained uninfected.

Kale predicted that fall armyworms at higher temperatures would cannibalize more because they need more food to keep up with an increased metabolism. They also predicted that fall armyworms that eat an infected caterpillar would be more likely to become infected at higher temperatures.

Featured scientists: Kale Rougeau from Louisiana State University

Flesch–Kincaid Reading Grade Level = 10.2

Additional teacher resources related to this Data Nugget include:

You can also watch a time-lapse video of Kale in the lab to get a glimpse of their work. Follow along as they check fall armyworm cadaver samples for baculovirus infection using a microscope
Kale also provided a video of baculovirus lysing, where occlusion bodies that encapsulate the virus are dissolved, confirming the presence of infection in the fall armyworm sample.
  • Read more about Kale’s hobby of participating and training for dog competitions on the Beyond the Bench blog.
  • More about fall armyworms here and here.
12.11.24

Little butterflies on the prairie

Butterfly on prairie flower.
A Tiger Swallowtail butterfly visiting a prairie flower to drink nectar.

The activities are as follows:

Butterflies are insects with colorful wings. You will often see them in a field, flying from flower to flower. Butterflies eat a sugary food made by flowers, called nectar. In return, the butterflies help the plants make seeds by moving pollen. As they travel from flower to flower, pollen is dropped off. This helps plants reproduce and make seeds. This is called pollination, and butterflies are pollinators. We need pollinators to grow many of the fruits and vegetables that we eat!

Prairies are habitats filled with many types of flowers. The Midwestern United States used to be covered in prairies. Today, most have been replaced by farm fields. Crops like corn and soybeans are commonly planted in the Midwest. Farm fields are important because we need land to grow our food. But this also means there is less food and habitat for butterflies.

Many farmers are concerned with growing our food while still protecting habitat for butterflies and other species. They want to know – how can we grow food for ourselves while still growing flowers for butterflies? A group of scientists in Michigan is working with farmers to think of solutions. The team is made of people from many different backgrounds and work experiences. The members of the team change over time, but typically 8 scientists are working together at a time. They all come together to brainstorm and do their research at the Kellogg Biological Station in Michigan.

Group of researchers ready to go out into field to butterfly survey.
Members of the Haddad Lab, ready to go out for a day of butterfly sampling in the prairie strips!

Prairie strips are a new idea that might help both farmers and the environment. These strips are small areas of prairie that can be added to farm fields. They look like rows of flowers and grasses within a field. They create habitat for many species, like butterflies, birds, ants, and even microscopic fungi and bacteria! Prairie strips may also help our food grow better by providing habitat for pollinators.

To figure out if prairie strips are able to draw in butterflies, the research team needed to collect data. They visited a large experiment that had many different kinds of farm fields. Some of the fields had prairie strips, while others did not. They thought prairie strips would help butterflies by adding habitat for them in farm fields that usually don’t have many flowers. They predicted they would see more butterflies in fields that have prairie strips and fewer in fields without these strips.

To count the butterflies in each type of field, the team went out on sunny spring and summer mornings when butterflies were flying around and eating nectar. They walked along the same paths in the same fields at the same time every week. Each time, they counted all the butterflies they saw within 5 meters. Each walk was 12 minutes long and followed a 150-meter path. They did these counts in 6 farm fields without prairie strips and 6 farm fields with prairie strips. The team counted butterflies like this 20 times over the summer. At the end of the summer, they added up all of the butterflies observed in each field. This number is called butterfly abundance.

Featured scientists: The Haddad Lab from Kellogg Biological Station Long Term Ecological Research Program – KBS LTER

Flesch–Kincaid Reading Grade Level = 7.3

10.24.24

A burning question

Fire crew in a woodland prescribed fire.

The activities are as follows:

Forests in the midwestern U.S. provide many important ecological services. They store carbon dioxide, which helps fight climate change. They also host a variety of plant and animal life. Forests provide spaces for recreation and support local economies through tourism.

Unfortunately, forests face threats. Climate change is causing more severe weather events, such as flooding and droughts. The spread of some parasites and diseases is also increasing as temperatures change. Forest managers are motivated to protect forest health. They can help combat these threats with their knowledge of different management practices.

Ellen and John have studied forest health in Wisconsin for decades. Ellen first became interested in nature while camping and hiking in Minnesota with her family when she was young. John became passionate about nature as a child while walking through the oak-hickory forests on his family farm. They teamed up with foresters from the Wisconsin Department of Natural Resources to examine the impact of prescribed fire as a management tool to increase forest health. A prescribed fire differs from a wildfire in that it is a planned fire that is set on purpose. When the conditions are right, forest managers will assign prescribed fires to specific areas to meet land management objectives. A lot of organization goes into prescribed fires to make sure the fire doesn’t spread or burn too hot.

Fire is part of the natural history of oak forests. They are adapted to recover quickly and they actually can benefit from fire. This is important for land managers who want to encourage the health of oak forests.

Ellen recording plant species diversity in a plot.

Oaks are considered a keystone species. This means they play a major role in maintaining ecosystem functions and the success of other species. There are two main reasons. First, they produce large amounts of acorns, which are food for many types of wildlife. Second, their canopies have more open spaces that allow light to reach the forest floor. Light is an important resource for plants, and smaller plants are limited by the shade of large trees. More light passing through the canopy allows more plants to grow below the oak trees. This increases the variety of species found in oak forests.

Ellen and John wanted to know if there were more plant species in oak forests that had prescribed fires. To answer their question, Ellen and John decided to study a part of the Madison School Forest in southwestern Wisconsin. This oak forest is special because research has been done on the impact of fire for over 75 years. In 1996, the forest was split into 15 units that have been under different management plans. One of the experimental treatments included prescribed fire at different frequencies. For example, the units in the prescribed fire treatment could have been burned every 1 to 4 years. Other units served as a control and were not burned. Comparing the control to plots that had been burned allows managers to see how often oak forests should be burned to increase forest health.

All of the management units were sampled in 1996 when the experiment first began and again in 2002 and 2007. In each sampling year, the number of plant species, or species richness, in the management units was counted. In 2023, Ellen, John, and their team resampled the plots to pick up this experiment where it was left off. This research will guide the best ways to support the health of oak forests and determine how important fire is to maintaining forest biodiversity. If fire is necessary to maintain oak forests, and oaks are a keystone species that support biodiversity, the research team expects to find higher biodiversity in plots where prescribed fire has been used.

Featured scientists: Ellen Damschen (she/her) and John Orrock (he/him) from
University of Wisconsin-Madison. Written by: Amy Workman (she/her)

Flesch–Kincaid Reading Grade Level = 8.8

9.23.24

Did you hear that? Inside the world of fruit fly mating songs

The activities are as follows:

Communication comes in all forms – through sound, smell, sight, touch, or even taste. The purpose of communication is to share some form of message or information to another organism. One form of communication between humans is talking, which is when we make a variety of noises as we speak using language. Just like people, animals make all kinds of noises to communicate with one another.

The tiny fruit flies that live on the ripe banana in your kitchen communicate as well. They use a courtship song when they are ready to mate. The male fly shakes his wings to sing a song to the female fly. The female fly hears the song, her brain processes the sound, and then she responds. Her brain decides whether she likes him or not. She may then try to kick him away or let him get closer.

Emma is a neuroscientist who is really interested in studying how brains are able to understand all kinds of communication. She uses fruit flies to figure out how brains process communication through sounds. Even though the fly brain is very small, they work a lot like human brains, so studying tiny flies singing to each other can help us understand our own brains.

While researching what other scientists had already learned about fly song, Emma read studies that described an interesting behavior called chaining. Chaining is a behavior when males chase and sing to each other. The scientists first observed this behavior when they played a fly song through a speaker for a group of 6 male flies. Emma wanted to see if she could repeat this behavior in her own lab. An important part of science is repeating experiments to make sure the results are accurate and can be achieved again and again. Repeating experiments can also be a way to test that another scientist’s methods work in your lab.

Sound is played through the yellow speaker. Flies are put into the chambers and watched for chaining

There are lots of things in the lab environment that can impact how a fly reacts to a song. Emma wants to pick a few variables to test. The first variable she selected is the volume of the courtship song being played. Emma decided to test different volumes to see how loudly she should play the fly song to get a response.

Since Emma couldn’t ask the flies if they could hear the sounds she played through her speaker, she measured chaining behavior instead. If the flies heard the sound from her recordings, she expected to see more chaining behavior.

Volume isn’t the only variable she can explore though. Imagine you are listening to a song and the singer sings a word you haven’t heard before. Do you think you’d be able to understand the word? The same thing may apply to the flies. Emma wanted to know if flies would react differently if they had been around other flies that sing. To test this, Emma raised some flies alone and others in groups. That way, she could see if being around other flies before the test made the song easier to recognize.

To gather her data, Emma put 6 male flies into a chamber with a clear top. She placed the chamber in front of a speaker. She also set up a camera to take a video of the flies for a minute before the song played and for a minute after the song began. This two-minute video allowed her to compare the flies’ behavior in silence with their behavior when the song plays. Then, Emma watched the video back and counted the number of flies that were chasing each other every 3 seconds. She did this for one whole minute (20 observation points) to get a chaining index for each group of flies.

Featured scientist: Emma Droste (she/her) from North Carolina State University

Flesch–Kincaid Reading Grade Level = 7.2

Students can listen to this audio clip of fly song and think about what these sounds may be communicating. The audio clip was generated by having a mating pair directly over a very sensitive microphone to capture the audio since it is not audible to the human ear.

9.23.24

Too hot to help? Friendship in a changing climate

This coral has lost its algae partners, causing it to be bleached. (Photo by Coffroth Lab)

The activities are as follows:

When given emergency instructions on a flight, you’re told to put on your own oxygen mask before assisting others. This is because if you run out of oxygen, you won’t be able to help others. Turning to nature, this same idea may be true when we look at relationships between two species.

Coral and certain types of algae form a mutualism where both species benefit from the partnership. Coral provides a safe home for algae, and algae make food for coral through photosynthesis. However, climate change is causing warmer ocean temperatures that stress the relationship. If the water gets too hot for algae, they can’t make food for the coral anymore. To survive, the algae must help themselves before they can help the coral.

Casey is a biologist interested in studying the changing coral-algae mutualism. He wants to know whether different individuals of the same algae species do better than others in warming waters. Individuals of the same species can have different traits. For example, each human person belongs to the same species, but each of us has different traits. This is largely because of our genetic composition for these traits, or genotypes. Casey set out to test if different algae genotypes were capable of being better mutualists under warm temperatures. If he could identify these genotypes, then maybe that could help protect coral in the future.

Casey gets a sample of algae from a flask in his lab. (Photo by David J. Hawkins)

Casey and his graduate student, Richard, set up experiments to test algae genotypes to see how well they performed at different temperatures. Casey and Richard grew five different genotypes of the same algae species in the lab. They used a pipette to transfer 10,000 cells of each genotype and placed them in flasks at two different temperatures. The lower temperature treatment is one where corals and their algae are usually happy: 26 degrees Celsius. The higher temperature treatment is where coral’s relationship with algae starts to break down: 30 degrees Celsius. At that temperature, many corals lose their algae entirely, in a process called coral bleaching.

Casey and Richard measured two things – the total amount of photosynthesis and the total amount of respiration happening in each flask. They did this by tracking what happened to oxygen over time. When there is a lot of photosynthesis, oxygen goes up, and when there is a lot of respiration, oxygen goes down. Two conditions are best for the mutualism. First, a lot of photosynthesis means the algae produced more food that they can share with coral. Second, less respiration means the algae used less of the food for themselves and have more to share with the coral. In summary, when the algae is stressed it does less photosynthesis and more respiration, making it a worse trading partner for coral. The best algae partner is the genotype that can photosynthesize the most and respire the least. The net food available is how much of the food made through photosynthesis is available after subtracting the food used by respiration.

Featured scientists: Casey terHorst (he/him) and Richard Rachman (he/him)

from California State University Northridge

Flesch–Kincaid Reading Grade Level = 8.9

Additional teacher resources related to this Data Nugget

8.28.24

Guppies on the move

Guppies in the lab. Photo Credit: Eva Fischer.

The activities are as follows:

Animal parents often choose where to have their offspring in the place that will give them the best chance at success. They look for places that have plentiful food, low risk of predation, and good climate.

Even though parents pick out these spots, individuals often move away from their birthplace at some point in their lives. Why do animals move away? There are risks that come with moving from one place to another. It can be dangerous to go through unknown places – potentially stumbling into predators or being exposed to diseases. But there can also be benefits to moving, such as discovering a better spot to live as an adult, finding mates, and spreading out to reduce competition.

As someone who loves to travel and has lived in four different countries, Isabela can relate! Isabela likes to see new places, try new foods, and learn new languages. But there can be drawbacks, and occasionally she finds it hard to be in a completely new place. Sometimes people don’t understand her accent, or she can’t understand them. She also misses her family when she is away. Knowing that traveling and moving can have such highs and lows for herself, Isabela wanted to know more about what motivates animals to seek out new places.

To follow her curiosity, Isabela found a graduate advisor who was also interested in animal movement. She joined Sarah’s lab because she had already collected data on the movement of small tropical fish called guppies. Sarah is part of a large collaborative project, where researchers from all over the world come together in Trinidad to study these fish populations.

When Sarah first started collecting data in this system, she wanted to track how far guppies move from one place to the next. She used established protocols from previous work in this system to set up a study. With the help of a team, she captured every fish in two similar streams for replication. Every fish that was caught was marked with a small tattoo so the research team could recognize it if it was found again in the future. She did this same procedure every month for 14 months. Each time she sampled the fish, she recorded the individuals that she found and where they were found.

Isabela used this dataset to ask whether guppies benefit from moving from one place to another. In this study, she focused on one type of benefit: having a higher number of offspring. It is through reproduction that animals are able to pass on their genes, so the more offspring an individual fish has, the more successful it is.

First, Isabela used the existing dataset to find out how far each fish moved: if Fish 1 was captured in Portion A of a stream in February and then in Portion B of the same stream in March, Isabela knew it had to move from A to B. She could use the timepoints to estimate how far each individual had traveled that month.

Second, Isabela used genetics to find out how many offspring each fish had. She looked at genetic markers to determine familial relationships between individuals in each stream. For example, two fish that shared 50% of their genes were probably a parent and an offspring. In this case, the older individual would be marked as the parent. Isabela used the genetic information to build a pedigree, or a chart that documents each generation of a population. That way she could track how many offspring each parent had produced.

She used these data to answer her question on whether there are benefits to traveling more. Isabela also wanted to compare whether the potential benefits of dispersal differed across the sexes. Males have to compete for females in order to mate. Isabela wanted to know if males that moved more were able to mate with more females and have more offspring.

Featured scientists: Isabela Borges (she/her) and Sarah Fitzpatrick (she/her) from the Kellogg Biological Station at Michigan State University.

Flesch–Kincaid Reading Grade Level = 8.3

Additional teacher resources related to this Data Nugget include:

If you or your students are interested in accessing more of the data behind this Data Nugget, you can download the full dataset from Isabella’s research and have students create graphs in Excel, Google Sheets, or using other data visualization software.

If students would like to learn more about Isabela, check out this Exploring with Scientists video from her time at the Kellogg Biological Station.

For more on this system and the research Sarah did in this study system, check out this unit and video on Galactic Polymath:

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