How did pumpkins evolve to be so weird? Biologists think they know why

They can be two pounds or 200, small and spherical or deformed and oblong, and display an array of colors, coats, and patterns. No, we’re not talking dogs, but squash – another genetically flexible lifeform that comes in a wide range of bizarre sizes and shapes, most of which (again, like dogs) can mate with each other despite being radically different. This genetic malleability is unique in the plant world: Apples, tomatoes, and oranges have plenty of genetic variation, but not three as many size differences as squash.

This genetic anomaly has a concomitant set of uses among humans—culinary, decorative, and Music. her pumpkins spicy seeds It can be turned into a snack or oil; Yellow squash can be cooked in cabbage Delicious pasta sauce; And the Bottle gourd with juicy warts It is a traditional home decor, especially during this time of year.

Genetically speaking, this is an amazing plant. So what is going on with pumpkins to allow for such an amazing natural variation? And what makes it biologically exotic compared to other plants?

The evolutionary history of squash intersects with that of mankind, as our beloved plants change with civilization. One could argue that, in a sense, the diversity of pumpkins is a testament to both human ingenuity and the wonders of the natural world.

“The origin of these crops – which play a huge factor in terms of diversity in shapes and genetics.”

Taxonomically, squash belongs to the family known as cucurbits – As Dr. Ajay Nair, chair of the Graduate Program in Permaculture at Iowa State University, told Salon, there are three main reasons why squash is so genetically diverse that it has been bred into subspecies as diverse as Giant pumpkin And the watermelon.

“If you look at the origin of the crops, where these crops originated from, that plays a huge factor in terms of diversity in shapes and genetics,” like the squash coming from South America or the snake squash that originated in India, Nair noted. He also noted that pumpkins have a lot of diversity in their gene pool: cucumbers only have 7 haploid chromosomes, while watermelon has 11 different chromosomes.

Finally, there is human intervention: “These crops have been around for a very long time, and humans have interacted with them. There have been a lot of very direct ways of selecting these crops, domesticating these crops and improving these crops,” Nair says.

Sometimes these factors complement each other, such as when humans take advantage of sterile squash Breed specialist designer pumpkins. However, human domestication sometimes limits the genetic diversity of squash, as explained by Heather R. Cates of the University of Florida Genetics Institute.

“When we compare a squash that shows a very wide variety of shapes, sizes, colors, and textures (Pumpkin maximum) to type no (Cucurbita Argyrosperma), species that have different shapes, sizes, colors, and textures do not appear to have suffered from the “domestication bottleneck” or reduced genetic diversity that characterizes many crops”. Domestication is done in the same way as other commonly used crops such as corn and bananas are cut in. While archaeologists can’t say with certainty the extent to which previous human civilizations inadvertently altered the genes of squash for their own purposes, it’s reasonable to suspect that it happened a bit.

“We can’t know for sure who is responsible for the genotypes or even the archaea that we observe in squash, but we do have evidence that thousands of years ago humans continued to cross or allow early domesticated squash species to cross with wild species,” Keats explained. It allowed the development of many types of gourds.

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Human interference in pumpkin farming is still going strong. South African researchers last year published an article In Frontiers in Sustainable Food Systems about the potential of bottle gourd. They noted that the glass gourd could be an essential food security crop, but not enough research has been done on it.

“There is wide genetic variation among bottle gourd genetic resources in Africa” that could be used for everything from creating better products to improving marketing, the authors wrote. “However, the crop has not been adequately researched and used, and improved varieties have yet to be developed and commercialized in the region.”

“Plant pathogens are expected to spread and infect plants more easily under current climate change scenarios.”

In addition to not being well studied, pumpkins may also be endangered due to humankind’s ecological irresponsibility. As with many other things, climate change may end up affecting humanity’s appetite for pumpkins. From Supercharged tornadoes And the Supply chain disruptions intensified Maybe even fueling epidemicsThe continued warming of Earth’s climate is changing our planet for the worse in countless ways. In this context, Keats noted, climate change will “intensify” the challenges faced by pumpkin growers and gardeners.

“Some plant pathogens are expected to spread and infect plants more easily under current climate change scenarios, and environmentally stressed squash and squash are more susceptible to initial infection and subsequent disease development,” Keats, also a postdoctoral researcher at the Florida Museum. Natural history noted. Changes in precipitation are also a threat pumpkinsEspecially for winter squash and pumpkin varieties that require high water inputs and bear fruits that are prone to rotting as they ripen. At the same time, “there are characteristics to growing squash that make it adaptable to climate change,” such as the fact that it’s pollinated by more species of bees, the fact that there’s a wide variety of species cultivated, and the fact that it’s versatile enough to grow in a wide range of climates. temperatures and altitudes.

This is good news for pumpkin, squash, and melon lovers, especially since holidays like Thanksgiving make pumpkins even more important. As Nair explained when asked about his favorite pumpkin, tastes and trends change over time.

“I think there’s been a shift toward a smaller, more decorative type of pumpkin or gourd that people would probably put on a plate or in front of their house,” Nair said. “I love it. I love those pumpkins just because they bring a different shade, a different color palette, a different texture. Not just those big pumpkins, but different shapes, different sizes, maybe even different colors at some point on the same squash. I love those squash.”

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