Convergent evolution: When species that are not closely related to each other acquire similar properties over time, similar structures are formed to perform similar functions in this process.
Divergent evolution: the development of closely related species with different characteristics over time.
Parallel evolution: is the acquisition of similar characteristics of closely related species over time.
One of the most prominent examples of convergent evolution is flight. The common ancestor of birds, bats and insects does not have wings. The wing structure has evolved separately in its own evolutionary path.
Although the purpose of wings is to fly, they are structurally different. The wings of bats consist of skin that fills between the very elongated finger bones.
In birds, wings consist of feathers on a skeleton containing overly fused hand bones. Insects have also developed wings of different structures. The evolution of flight probably started with flying short distances and then evolved into long distances.
During this process, the density of the bones began to decrease as adaptation to flight. The wings, on the other hand, have developed from hand-like structures if examined carefully. The architecture that starts with hand can turn into wings and specialize again to swim on the wings like in penguins.
Dolphins and whales are often confused with fish, but dolphins are mammals and their ancestors are a four-legged animal. Creatures from different conditions that have begun to adapt to the marine ecosystem, Ichthyosaur, Dolphin, and shark have achieved aerodynamic body plans optimized for swimming and hunting in water.
These three creatures come from different areas, the ancestor of the Ichthyosaur was the reptile, the dolphin’s mammal and the shark fish. Similar solutions have been found under similar evolutionary pressure.
Living on land is not much affected by air resistance, but water is 784 times denser than air, so the evolutionary pressure on living things is higher. In order to move in the aquatic environment, the resistance must be reduced to the lowest level.
The fins of whales, fish, and penguins converge to similar architectures, optimizing them to minimize friction in the aquatic environment.
Eyes are very important to living beings because they help perceive information coming from the environment at the speed of light. Even a living being that has a less developed eye that does not have lenses and can only measure the change in the amount of light will have a great advantage.
Eyes have been invented at least 40 times in the course of evolution. Although they have different architectures, their functions are similar.
There are 2 blind spots in the human eye, but due to the architectural difference, there are no blind spots in the octopus.This difference is probably due to the development of the eye’s brain tissue in the human eye and the skin tissue in the octopus.
As humans migrated north, their skin and eye colors began to lighten. This adaptation is most likely related to reduced sunbathing time and vitamin D production as they move north. This adaptation is not specific to humans; similar skin and eye color variations can be seen in different mammal species.
Carnivore in plants
Many examples of convergent evolution can be found in plants as well. Although we have the perception that animals eat plants, there are also plants that can eat animals.
One of the most important factors for convergent evolution to take place is that living things live under similar environmental conditions. Carnivorous plants live in washed soils with low mineral value.
There are basic elements that plants need to take from the soil in order to grow, such as Nitrogen, Phosphorus, Potassium, etc. Since these elements are not available in sufficient amounts in the soil, carnivorous plants meet their needs by eating insects, mice and even birds.
Hunting techniques can vary, the Flytrap has an active trap, capturing and digesting its prey very quickly. Sarracenia or Nepenthes have developed passive traps in the shape of jugs similar to convergent evolution.
Traps are leaves in the past, specialized in hunting for time, while defensive enzymes used against insects are specialized for digestion.
If plants disappeared, we would probably go hungry. They produce energy that can be used by animals by processing solar energy and inorganic materials. In this process, mutual win-win relationships between flowers, fruits, animals and insects have developed.
Flowers reward bees and insects with nectar, insects unconsciously carry pollen and help the plant increase its genetic diversity. Similarly, some plants reward and use fruit and animals to spread their seeds over larger areas.
The spread of seeds over large areas reduces the competition of the parent plant and offspring for sources such as sunlight and increases the chances of survival of the seeds, since they are not collected in a single point.
Until the seeds ripen, the fruits are partially inedible for animals and sometimes the fruits are toxic.
When airplanes were first invented, there were many designs, for example, the number of wings, the structure and the materials used were different.
Today, the designs of the aircraft are very similar to each other, a certain model has been achieved with the optimization process aimed at minimizing air friction and being the lightest and most durable.
The convergence in design can be seen in cars, ships, telephones, homes and many other places.
Evolution is not deterministic, given an environmental condition, the living creatures living here cannot be predicted exactly. If different versions of the organism’s body plan and behavior in a particular environment are converted into a compatibility score, we can reach a mathematical field reminiscent of mountains and rivers.
In the evolutionary process, living things will try to move towards the optimum point in this area and optimize their survival success. There may be many optimum points, and if living things starting from different points reach similar points, they constitute an example of convergent evolution.
Evolution itself must also be convergent. If another life is found in the universe, it will most likely have an evolutionary process similar to that on Earth. Other possibilities other than a self-replicating algorithm do not seem very logical.