Evolutionary Biology

Pictured above are petroglyphs on Newspaper Rock at Petrified Forest National Park. I stopped there briefly with my sister and our two kids during the summer of 2023, when I took this series of pictures. There is so much to process here. It is one of the most densely packed collection of petroglyphs I have ever seen. I was in awe. The people who left their mark here lived thousands of years ago. Yet, here we are, connected across space and time. The cultural significance here is evident by how protected this area is. I was lucky to have a camera powerful enough to capture such clear images, we were at least 100 yards away. It is also evidence of how ancestral humans evolved not only spoken language, but written language as well.

I took this picture last winter in Washington state. From the image, we can surmise that the trees pictured share genetic lineage. To verify that, we would have to genetically sequence a sample of them and see if they are truly related or if they only share morphological similarities. It is likely that they are closely genetically related since the seeds dispersed by these trees are not going to go far. I also chose this picture because it felt like a fun play on "family tree".

Even though all these animals look completely different, they are technically part of the same species. It is technically possible for any of these dogs to mate and produce viable offspring. (Not the dogs pictured though, they were all fixed because I am a responsible pet owner). This is why we can have insane breed combinations. However, there are also dogs that have bred with wolves, resulting in hybrids that are reproductively capable. These two species have a close common ancestor, but it is still surprising that successful matings are possible.

Pictured above is a globemallow been sleeping in a desert globemallow flower. I took this the summer I worked at Pipe Spring. This photograph is a great example of coevolution. The survival of the two species is tightly intertwined. This particular bee species is specialized in pollinating these particular flowers. If these bees were to die out, the flowers would not get pollinated, at least not to the degree they currently are. In this way, these two organisms have developed a mutualistic relationship. They depend on each other to survive. Generally we think of abiotic factors affecting evolution and fitness of species, particularly how these organisms fit into their environment and how well suited they are for the climate they live in. We tend to forget that the other living things are ALSO part of the same environment and, therefore, have an effect on fitness and evolution.

In evolution, altruism refers to an action that is costly to fitness and does not benefit the individual directly. Above, there are two pictures of my friend's arm during plasma donation, a picture of my best friend, and a group picture of my best friend's dad, two of her good friends, my god daughter, my best friend, and I(from left to right). I chose these pictures to discuss social and reproductive altruism. Donating plasma is costly to fitness in that is removes vital bodily fluids, without any direct benefit to the individual. One can only hope that enough people are also donating, that way it can serve us as well. My best friend is adopted. Her adoptive mother demonstrated reproductive altruism in foregoing the opportunity to have biological children and passing on her genes. The group picture shows how social altruism helps build a community. Although there is no direct benefit to being another adult in my god daughter's life, I'm happy to do it. It often comes at the cost of time, money, and energy, AND it is also very rewarding. The group photo shows us supporting her at a band recital that she had been preparing for all semester. In this way, the time and energy expended by those of us without a genetic link to this amazing kid helps raise future generations of amazing adults.

This gorgeous guy was walking around outside of the visitor center at Pipe Spring. It is probably a male Desert Tarantula. I love late July and August for this very reason: it's tarantula season! The most interesting thing about this species to me is that the males walk a few miles to find willing female mates. This relates to sexual selection in that the males willing to walk (and survive their walks!) have the highest likelihood to find a willing mate. The females wait for a suitor, making them the "choosers" in this arrangement.

This was the most magical hike I have ever been on. My sister took my friend and I out to Lava Point to go rock hounding and we found these precious babies instead. California Condors are an endangered species. I chose this species to talk about nonrandom mating to illustrate the fact that mating is species specific. If it weren't, we could have much more easily rehabilitated them by crossing them with turkey vultures or some other corvid. Two Condors reproducing will always have Condor offspring. And luckily, there are much more Condors in the wild now than there have been in decades. Which is why we got to see four adults and one baby perched on trees at Lava Point. It was incredible and I don't think anything will ever top that moment. Probably.

I took so many pictures during my summer at Pipe Spring. This is one I took from the top of the hill behind the main grounds. When I first came to work there for the summer, I got told a story about the grasslands here. Before colonists moved into the area to graze their cattle and take over the resources, there was a grassland here. They say that the grasses were "belly high to a horse", and they stretched across the land as far as the eye could see. With the introduction of cattle, the grasslands were transformed into what you see today; a desert shrubland. I bring this up to illustrate the effect of non-native species on geneflow and genetic drift. The cows ate all of the native grasses, which pushed the native wildlife out of the area in search of more food. The native grasses that were once utilized by both the native wildlife and the Indigenous peoples as sustenance were decimated, almost to the point of extinction. The shrubs that remain(at least the native ones), were left because they were able to withstand the impact of the non-native species.

Another sample from the ponds at Pipe Spring National Monument. During my internship there I spent a lot of time looking through the microscope. Looking at the water with the naked eye, especially after collecting a sample, it just looked empty. A clear jar full of clear liquid. But under the microscope: multitudes. I used a picture of these little guys in my introduction post, and I'd like to talk about them some more. I think they make an excellent argument for genetic mutations and how they are generally preserved only when advantageous. The spiral shape probably developed as a mutation during replication and survived because it gave the cell motility, allowing for better survival.

This is a video I took from a water sample at the ponds at Pipe Spring National Monument via microscope. I'm not entirely sure what I'm looking at, but I can see that some of the specimens are moving independently, and some not at all. Some of the microbes in the video have adapted to their environment and have developed the ability to swim in a particular direction. This is a prime example of Natural Selection. Over however many generations, these microorganisms developed the ability to identify in which direction to swim, whether that be in the direction of food, or to flee from danger. More importantly, they developed the ability to move at all. They have the option to flee or follow because they evolved beyond a stationary life.

Welcome to Evolutionary Biology, I'm excited to explore these theories with you!