Learn about evolutionary compromises; the fractals of Romanesco cauliflower; and dolphins that learn each other’s names. Conflict traits: when evolution and mating conflict with each other by Cameron Duke Experiments show natural selection opposes sexual selection. (2021). EurekAlert! https://www.eurekalert.org/pub_releases/2021-06/uoe-esn060721.php Mulder, M. B., & Rauch, K. L. (2009). Sexual conflict in humans: Variations and solutions. Evolutionary Anthropology: Issues, News, and Reviews, 18(5), 201–214. https://doi.org/10.1002/evan.20226 Okada, K., Katsuki, M., Sharma, M. D., Kiyose, K., Seko, T., Okada, Y., Wilson, A. J., & Hosken, D. J. (2021). Natural selection increases female fitness by reversing the exaggeration of a male sexually selected trait. Nature Communications, 12(1). https://doi.org/10.1038/s41467-021-23804-7 Here's why Romanesco cauliflower grows in a fractal pattern by Briana Brownell Ouellette, J. (2021, July 8). What fractals, Fibonacci, and the golden ratio have to do with cauliflower. Ars Technica; Ars Technica. https://arstechnica.com/science/2021/07/what-fractals-fibonacci-and-the-golden-ratio-have-to-do-with-cauliflower/ Azpeitia, E., Tichtinsky, G., Le Masson, M., Serrano-Mislata, A., Lucas, J., Gregis, V., Gimenez, C., Prunet, N., Farcot, E., Kater, M. M., Bradley, D., Madueño, F., Godin, C., & Parcy, F. (2021). Cauliflower fractal forms arise from perturbations of floral gene networks. Science, 373(6551), 192–197. https://doi.org/10.1126/science.abg5999 Dolphins can learn each other's names by Grant Currin Morell, V. (2021, April 22). Dolphins learn the “names” of their friends to form teams—a first in animal kingdom. Science | AAAS. https://www.sciencemag.org/news/2021/04/dolphins-learn-names-their-friends-form-teams-first-animal-kingdom King, S. L., Connor, R. C., Krützen, M., & Allen, S. J. (2021). Cooperation-based concept formation in male bottlenose dolphins. Nature Communications, 12(1). https://doi.org/10.1038/s41467-021-22668-1 Shyr, L. (2021, May 5). Dolphins Help Those Who’ve Helped Them Before, Even When They’re Not Friends. Atlas Obscura; Atlas Obscura. https://www.atlasobscura.com/articles/dolphins-work-in-teams Follow Curiosity Daily on your favorite podcast app to learn something new every day withCody Gough andAshley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Learn about evolutionary compromises; the fractals of Romanesco cauliflower; and dolphins that learn each other’s names.
Conflict traits: when evolution and mating conflict with each other by Cameron Duke
Here's why Romanesco cauliflower grows in a fractal pattern by Briana Brownell
Dolphins can learn each other's names by Grant Currin
Follow Curiosity Daily on your favorite podcast app to learn something new every day with Cody Gough and Ashley Hamer. Still curious? Get exclusive science shows, nature documentaries, and more real-life entertainment on discovery+! Go to https://discoveryplus.com/curiosity to start your 7-day free trial. discovery+ is currently only available for US subscribers.
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/romanesco-fractals-dolphin-names-evolution-vs-mating
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about what happens when evolution and mating conflict with each other; the weird reason why romanesco grows in a fractal pattern; and why dolphins learn each other’s names.
CODY: Let’s satisfy some curiosity.
Evolution happens in a few different ways. The two most well known ways are natural selection, which is about survival, and sexual selection, which is about mate choice. They’re basically two processes with the same end goal. But in practice, they don’t always get along all that well. That’s right: sometimes sex is the enemy of survival.
Most of the time, natural selection and sexual selection jive just fine. For example, forest birds called peafowl (aka peacocks) evolve by natural selection, which weeds out the birds that don’t peafowl well enough. The males, with their big, colorful peacock tails, look like that as a product of sexual selection. The females like their extravagant feathers, and having those feathers is a sign that the male is healthy and a good mate. I mean, he must be if he can survive in spite of his ridiculous plumage. If she mates with him, there’s a good chance they’ll have lots of healthy babies.
But other times, the forces work in the opposite directions, like hitting the accelerator and the brake at the same time.
A recent study at the University of Exeter demonstrated that evolutionary dissonance with broad-horned flour beetles. These are little brown bugs that are commonly found feasting on wheat. The males of this species all have big mandibles they use to fight each other. The winners get to pass on their genes, so the guys with the biggest mandibles tend to be the ones mating and passing on giant jaw genes.
While the females don’t have massive mandibles themselves, they inherit the genes for a body that can support them. This means they get a big head and neck and a smaller abdomen. That’s a problem. It limits the number of eggs the females can produce.
The researchers looked at what would happen if they removed the big mandibled males from the population. Spoiler alert: It was really good for the females. After eight generations, females were producing 20 percent more eggs on average than the control group. So, in essence, sexual selection in this species is reducing the number of babies they can have.
This kind of thing is actually really common. Scientists call them conflict traits, and they are thought of as evolutionary compromises. For example, in humans, females would benefit from wider hips for easier, safer childbirth, but males would ideally have narrower hips for easier movement. Instead of the sexes having their optimal body type, there’s a tug of war.
In the immortal words of Mick Jagger, You can’t always get what you want.
Today, I’m going to explain the biology behind one of the prettiest vegetables there is. Get ready to learn about the Romanesco cauliflower.
For centuries, humans have been fascinated with shapes where each small part looks like the whole, like clouds and shorelines. But for most of history, these shapes defied mathematical definitions. Finally in 1975, Benoit Mandelbrot [ben-WAH MAN-dull-brot] studied them in detail, and named them: fractals.
Fractal patterns have a special feature called self-similarity. Self-similarity is when a pattern looks the same at various different scales. That means that the pattern you see at one magnification will be the same pattern you see at a different magnification.
Scientists in many fields have noticed that fractal patterns are often found in nature, everywhere from our lungs and blood vessels to ferns and flowers.
But one natural example of a fractal has continued to perplex scientists: the Romanesco cauliflower.
Romanesco cauliflower is an edible vegetable related to cauliflower and broccoli, and it has a very distinctive appearance. Instead of branching out like a fluffy treetop, the head of the Romanesco cauliflower swirls with spiraling rows of self-similar fractal peaks.
Humans have been eating this strangely-shaped vegetable since the 16th century in Italy, hence the Roman in Romanesco. But it was only recently that scientists have figured out how Romanesco cauliflower gets its peculiar shape.
In all cauliflower, from the white kind you find in veggie trays to the fancy green Romanesco, the part that you eat is actually made up of failed flower buds. The cauliflower produces buds, but those buds never actually develop into flowers. Instead, they turn into stems, and those stems do the same thing… produce buds that instead develop into stems that produce buds that instead develop into stems…. You get the idea.
This recursive process is what lets them continue to grow, and what makes the head of the vegetable we eat.
But if all cauliflower grows the same way, why does the Romanesco cauliflower look so different?
New research from an international team has finally explained why, using a combination of biology and computer simulations.
Turns out, it’s how fast the plant produces those buds and stems that’s the key. Unlike regular cauliflower that produces buds at a consistent rate, Romanesco cauliflower starts producing buds faster and faster and faster until the new buds are just too small to produce more.
This goes to show how just one small change to the development path of a plant can produce a characteristic that’s completely distinctive…. and delicious.
New research shows that dolphins don’t just have friends: they have serious allies. And they recognize those allies by name — or, more accurately, by whistle.
Researchers working in Australia’s Shark Bay have been using underwater microphones and drones carrying video cameras to spy on a population of Indo-Pacific bottlenose dolphins that call that water home.
See, for the last 30 years, these researchers and their colleagues have been following the social drama of these dolphins. Male dolphins make different types of strong alliances, almost always to help in mating. Males that are looking to find and corral a fertile female cooperate in groups of two or three. That’s called a first-order alliance. Those are important, but they aren’t necessarily long-lasting. Second-order alliances contain groups of up to 14 individuals, and they last for decades — probably whole lifetimes. The males in a second-order alliance work to keep other males from quote-unquote “stealing” the females they’ve corralled. Dolphins even have third-order alliances made up of multiple other alliances.
The big mystery was how these dolphins keep track of such a complicated social hierarchy. Researchers already knew that dolphins have names — every dolphin gets a signature whistle from their mother. The team wondered if dolphins kept track of each other using these whistles.
They spent two years eavesdropping on the dolphins to match individuals with their whistles. Next, they played the whistles they’d recorded while other allied dolphins were around.
90 percent of the time, the males who heard the signature whistle of a second-order alliance member immediately turned to face the source of the whistle. Their reaction wasn’t as strong with first- and third-order alliance members. Second-order alliances involve dolphins who have helped each other in the past — not necessarily dolphins who like to hang out together. So the strong reaction these dolphins had to the “names” of their second-order allies is an indication that dolphins have a concept of team membership. It’s the first time that’s been seen in any non-human animal.
The results also show the tremendous importance of whistles in dolphin social life. If you’re gonna collaborate with someone for 40 years, you’ve got to be able to recognize them. Turns out it’s whistles that make that possible, or at least play a big part.
These findings are pretty important for researchers who study the social behavior of dolphins, but there are still a lot of questions left to be answered. One big one has to do with the females: what do they whistle about?
Let’s recap what we learned today to wrap up. Starting with
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ASHLEY: Today’s writers were Cameron Duke, Briana Brownell, and Grant Currin.
CODY: Our managing editor is Ashley Hamer.
ASHLEY: Our producer and audio editor is Cody Gough.
CODY: [AD LIB SOMETHING FUNNY] Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!