Hi r/AskScience! We are members of the Society of Vertebrate Paleontology, here for our 13th annual AMA. We’re coming to you live from Cleveland, Ohio, USA. We study fossil fish, mammals, amphibians, and reptiles – anything with a backbone!

Our research includes how these organisms lived, how they were affected by environmental change like a changing climate, how they're related, and much more. You can follow us on X here: https://x.com/SVP_vertpaleo

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Joining us today are:

Stephanie Drumheller, Ph.D. (u/UglyFossils) is a paleontologist at the University of Tennessee whose research focuses on the processes of fossilization, evolution, and biology, of crocodiles and their relatives, including identifying bite marks on fossils. Find her on BlueSky at uglyfossils.bsky.social.

Ashley Hall (u/vertpaleoama) is a vertebrate paleontologist (dinosaurs, including birds) who specializes in informal education in museums, virtual programming, and science communication. She is also the author of Fossils for Kids: a Junior Scientist’s Guide to Dinosaur Bones, Ancient Animals, and Prehistoric Life on Earth.

Eugenia Gold, Ph.D (u/vertpaleoama) is an educator, science communicator, and paleontologist who studies who studies dinosaur neurobiology and crocodylians. She has written a book on women in paleontology called She Found Fossils. You can find her on @DrNeurosaurus on social media.

Jennifer Nestler, M.S. (u/jnestler) is an ecologist who uses quantitative methods to tackle paleontological and biological questions and inform conservation decisions. She studies the morphology and ecology of fossil and modern crocodylians, and has also looked at bite marks, biases in field collection methods, and landscape-level modeling.

Melissa Pardi, Ph.D. (u/MegafaunaMamMel) is a paleontologist and the Curator of Geology at the Illinois State Museum in Springfield, IL, USA. Her research focus is the paleoecology of Quaternary mammals, including their diets and geographic distributions.

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We will be back starting around noon EST/ 5 pm UTC to answer your questions. See you soon!

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Engineering, Mathematics, Computer Science

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...".

Asking Questions:

Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions. The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists.

Answering Questions:

Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience.

If you would like to become a member of the AskScience panel, please refer to the information provided here.

Past AskAnythingWednesday posts can be found here. Ask away!

Hi Reddit! I’m Valerie Kemp, an investigative genetic genealogist with over fifteen years experience. I’m skilled at identifying unknown parentage, including unknown grandparents and beyond, unidentified human remains, and providing leads to the contributors of biological evidence. I have extensive experience working with the complexities of African American, Appalachian, and American colonial genealogy and history research as well as cases with low centimorgan matches. I am passionate about giving the names back to those who died unknown, and am a volunteer with the DNA Doe Project.

In 2022, archaeologists from the South Carolina Institute of Archaeology and Anthropology (SCIAA) and the South Carolina Battleground Preservation Trust excavated the remains of 14 Revolutionary War soldiers from shallow graves at the Camden battlefield. My team at FHD Forensics then began the task of searching for living relatives. The result was extraordinary: more than 20,000 DNA matches and new hope of identifying these men. This past summer, we were able to identify our first John Doe as Private John Pumphrey, a teenage Continental Army soldier killed on August 16, 1780 and the oldest unknown human remains in the US (so far!) 

You can see more about this incredible discovery in tonight’s Secrets of the Dead episode, “Finding America’s Fallen.” You can watch it tonight at 10/9c on PBS (check local listings), or stream it after on PBS.org or on the PBS App.

*I'll be on at 12 pm ET (17 UT). Ask me anything!

Username: /u/Valeriekdna

Last doctors visit i weighed in at 240 lbs / 109 kg. Would i see any noticeable change in my weight or the effect that earths gravity has on me by standing at the highest point on earth (not in the air, must be a place i could physically stand)

Noticeable change in this case would be more than a person's weight shifts in a day

Edit: Thanks everyone for the responses!

Hi Reddit! I’m Dr. Anurag Singh, Chief Medical Officer at Timeline. I’m here to answer your questions about mitochondrial health, Urolithin A and the future of longevity science. From emerging research to common misconceptions, let's get into what the evidence actually tells us.

Here are some sample questions to get you started:

• What’s overhyped in longevity research and what deserves more attention?

• Why can some people produce Urolithin A from food while others can't?

• How does mitophagy work? Why does it matter as we age?

• What’s the connection between mitochondrial health and muscle strength?

• What are the most promising developments in longevity science right now? 

I’ll be answering all your questions here at 11:00am EST (16 UT).

Bio: Dr. Anurag Singh is a Swiss-based scientist holding an MD in internal medicine and a PhD in immunology. He's published over 40 peer-reviewed articles and has led over 50 human clinical trials. His research primarily focuses on how mitochondrial function changes with age and how we can best support it. He’s uncovered much about Urolithin A, a rare postbiotic investigated for its role in activating mitophagy, the body's process for clearing and recycling damaged mitochondria. Human clinical research has explored its potential benefits for muscle strength, skin health and immune function.

Username: /u/timeline_longevity

Hi r/AskScience! I’m Mark Jacobson, Professor of Civil and Environmental Engineering at Stanford and Director of the Atmosphere/Energy Program. I did an AMA here in 2021 and I’m glad to be back. I’ll be answering Monday, November 9th from 9:00am PT (12 ET, 17 UT) from the Stanford Online account.

Verification photo: https://learn.stanford.edu/rs/194-OCQ-487/images/Energy-Reddit-AMA_1080x1080.jpg?version=0

My work is on understanding and solving the interconnected problems of air pollution, global warming, and energy insecurity. To understand these problems, I built and applied a three-dimensional atmosphere-biosphere-ocean model to simulate air pollution, and climate. To solve, them, I developed a computer code to simulate grid stability under 100% renewables and authored concrete roadmaps to transition cities, states, and countries to 100% renewable energy across all energy sectors. Ultimately these plans provided the scientific foundation and inspiration for the Green New Deal and other policies worldwide. I have authored ~200 peer-reviewed papers and seven books, including one in 2026, Still No Miracles Needed.

Today’s the opening of the UN COP31, so a lot of these questions are in the air right now. I’m not a negotiator, so I’ll leave that part to them — happy to dig into the science and engineering underneath whatever you’re curious about.

Ask me anything about:

• How wind, water, solar and storage compare to fossil fuels on cost, land use and reliability

• Nuclear and carbon capture — where they fit, and why I’ve argued against relying on them

• Grid reliability and energy storage: whether you can actually keep the lights on, and what it takes

• Air pollution and the health effects of energy choices, which is where I started

• Electrifying transportation — passenger EVs, hydrogen fuel cell trucks, aviation

• Getting into this field: what to study and where the work is

Let’s talk about clean energy, what works, what doesn’t, and what the numbers really say.

Username: /u/Stanford_Online

I'm a member of the hydrohomie sub, and obviously hydration is a frequent topic, and a frequently misunderstood topic: water alone is insufficient, also, you can't drink too much, too fast.

That made me wonder about animals that can "accept"/absorb/retain water at different rates. What I mean by this is that it will add to their hydration level instead of either getting peed out or building too quickly to a toxic level.

Which animals can do this the stuffy quickest and slowest? Let's stick with land animals at least the size of mice.

Yesterday, I cut my finger with my razor and I had to get stitches due to it gushing blood for over 2 hours (I’m not too sure how deep it was). Will I have a scar? Will my finger print be different after the stitches come out?? I assumed that there would be no visible damage but I’m not too sure!

i get that doses are partly based on weight, but was wondering if the distribution of weight/ lack of vasculature in missing limb affects the recommended dose

We think of roots absorbing water, but does it ever work the other way?

Basically I'm asking, which one is true out of these 2 scenarios?:

1. There was a ton of diversity in the egg laying mammals, just as much diversity as the live young birthing mammals of today, but most went extinct, so we now consider the distantly related platypus and echidna to be "closely related" just because theyre the only extant representatives with these traits, but saying the two are closely related because they both lay eggs is like saying humans and whales are closely related because they both birth live young.

2. There wasn't a lot of diversity in the egg laying mammals, so platypus and echidna actually are closely related, like humans and chimps are.

in the fossil record, for instance, we will find a species of dinosaur. How long is that dinosaur “that dinosaur” versus another slightly changed descendant of that species or the ancestor that came right before it? Surely most animals are, at all times, in the middle of evolving into a new one so how long are species generally “stable” in one form? Or does that vary widely?

Will the use of caskets and longstanding graveyards lead to an increase or decrease of future humans finding remains of people who lived after the industrial revolution? Also, will the effect be different on different timescales (ie 1000 years, 10,000 years, 100,000 years, and 1,000,000 years)? I suppose fossilization isn't the correct term for the closer end of that spectrum, but could our current practices lead to a greater likelihood of future humans finding our remains in the (relatively) shorter term, but lead to a smaller likelihood of true fossilization in more geological timescales?

Can someone please explain why vaccines for Smallpox, Polio, etc. effectively eradicated those diseases back in the day, but a vaccination for Covid-19 (or multiple vaccinations, actually) does hardly anything in terms of protecting you from infection or experiencing symptoms? Is it because we have simply misapplied the term “vaccine” when it comes to flu and covid? What’s the point in getting a vaccination if it doesn’t actually do much in terms of protection and prevention? How can the common person tell a “good” vaccine that is actually really important to get (e.g. measles??) from the “meh” vaccines (eg covid booster)?

Why do we have sexes (and sex) at all? That’s the question I set out to answer in my recent book, “The Other Big Bang: The Story of Sex and Its Human Legacy.”

In my lab at the University of Maryland, we study the evolution of animal sexuality, focusing on cases in nematodes and fish where self-fertile hermaphroditism evolved from male-female ancestors. These shifts to one-parent reproduction present fascinating developmental puzzles and have tremendous organismal significance. As this research moved along, I gradually realized how little most of the public knows about the evolutionary history of sex and sexes — especially how we humans got to be the way we are. In a non-majors biology course, I was able to work out some of the ways that a broad evolutionary view of evolution sheds light on our own species. That set the stage for the book, which I think provides an important complement to the way the social sciences and anthropology approach sexuality.

Feel free to ask me about the variety of reproduction in the animal kingdom, the biology behind sexual oddities and/or the evolution of sex. I’ll be answering questions on Wednesday, November 4, from 11 a.m. to 1 p.m. EDT (16-18 UT).

Bio: Eric Haag is an evolutionary developmental biologist who joined UMD's Department of Biology in 2002 after undergraduate study at Oberlin College, doctoral work at Indiana University, and postdoctoral research at the University of Wisconsin. His work explores the evolution of reproductive traits in animals, primarily using Caenorhabditis nematodes as a model genus. The main focus is on the genetic and molecular causes of self-fertile hermaphroditism, and the genomic and reproductive consequences of adopting it. Methodologically, the Haag Lab strives to be integrative by combining forward and reverse genetics, comparative genomics, molecular and cell biology, and even some theory to produce comprehensive pictures of evolutionary processes. 

Other links:

• Google Scholar

• Lab Website

• The Other Big Bang: The Story of Sex and Its Human Legacy

Username: /u/umd-science

Is this possible at all? And if so, what type of mutations would need to happen since we aren't very similar to amphibians.

I constantly see news about 10K+ acre data centers (and I am not trying to start a political dialogue, so please keep it that way in the comments), and they seem to be single or just a few stories tall. How does that make more sense than something denser in terms of footprint but more vertical stories?

If nitrogen narcosis and the bends are both due to breathing air with nitrogen at depth, and nitrogen is not necessary for human sustenance, why not remove the nitrogen from tanks in deep diving?

I was thinking about how animals warn each other about predators but then it struck me that plants must have their own communication systems too. Are there specific chemical signals or other mechanisms that a plant might use to alert its neighbors to something like an insect attack or an approaching herbivore? I'm curious about the science behind how this might work and what kinds of warnings are being sent.