Thread by @__Helicon__

Let’s talk about #Evolution. We’ve all had that dispute with a #Creationist that uses any desperate measure to attempt to prove intelligent design over Evolution.

There are modern day examples of how Evolution works and I will explore several of them.

Part 1: Human Evolution

Vestigial traits are examples of leftover muscles that Evolution has kept in some humans. Everyone knows someone who can move their ears, but can you? These muscles are auricle & are found in Dogs/Cats & are used to direct ears towards sounds.

The human brain is shrinking, and one theory suggests that a smaller brain is more efficient, and is gradually being rewired to work faster & take up less room. Is the brain shrinking to solve problems, and inhibit violent traits?

Hypoxia (mountain sickness) can range from headaches, to nausea & impaired thinking & is due to lack of oxygen in the atmosphere at high altitudes.

Andean inhabitants would have suffered greatly when they initially chose to live at high altitudes, but the human body can adapt, & to combat hypoxia the human body starts to carry more oxygen in red blood cells, thus making the people able to withstand the high altitudes.

Tibetans do it different than Andeans in that they do it respiratory by taking more breaths to compensate for lack of oxygen. Studies have also found that they have developed larger blood vessels that allow them to carry more oxygen, & they they have higher levels of hemoglobin.

Genetic mutations have also been studied in the Inuits of Greenland & their bodies have adapted due to their poor diets that control how the body uses fat which provides the clearest evidence to date that human populations are adapted to particular diets

The Inuit diet is an example of how high levels of omega-3 fatty acids can counterbalance the bad health effects of a high-fat diet.

Dr Pascale Gerbault (UCL Genetics, Evolution & Environment and UCL Anthropology), who co-authored the study, said: "These findings give us important clues about how our diet and the way we metabolise our food has affected and probably still affects our evolution.”

Inuits have also been said to have more brown fat than inhabitants of warmer climates which burns energy to create heat.

Most animals have the the Jacobson's organ & it is part of the vomeronasal system. Humans also have it, but it’s now redundant.

Animals use it to seek pheromones, or marks that another animal has left so they can determine the sex. Scientists have found that in humans it potentially stopped working a long time ago & there are no nerve endings found connecting to the brain.

Ever seen a Chimp use its back feet like hands so they can grip branches? This is because of the Plantaris Muscle. Humans also have this muscle but it’s superficial as we have no real use for it anymore, & a percentage of humans are now even born without it.

Wisdom teeth were needed when our ancestors needed to eat plants in a hurry to get enough food to get the nutrients needed when foraging. As human diets changed the third molar became redundant, & some people will live their entire life without them developing.

Another vestigial feature of humans is the third eyelid (Nictitating membrane)(plica semilunaris). In Gorillas this is still active, but in one of our closest relatives, the chimpanzee, it also appears to be dormant.

Most animals that use the third eyelid have it for protection, & to keep the eye clean. Why humans have evolved away is unknown, but it may be because of change of habitat & no natural predators.

The appendix which has been long known to be a useless evolutionary artifact can be removed with no harm to a person. The reasoning as to why we have it is unknown, but some scientists believe it to have once been part of the cecum which extinct ancestors used to help digestion.

My final example of human vestigiality is the coccyx, which is the remnants of a mammalian tail, which can consist of 3 to 5 bones. Whilst it serves no purpose as a tail anymore it does help hold certain essential bodily muscles and ligaments in place.

Part 2: Evolution in the Animal Kingdom.

The green lizards of Florida are one of the best examples of how fast Evolution can happen. When the brown lizards decided to occupy the same habitat the green lizards had no option but to go higher up in the trees.

In just 15 years the toe pads grew & got stickier to be able to stay attached to the slimmer, smoother branches.

They were studied over roughly 20 generations by the College of Natural Sciences at The University of Texas in Austin.

The cave dwelling Mexican tetra (Astyanax mexicanus) have no need for sight, so Evolution has taken away their eyes.

Due to the energy & brain power required for sight being removed, this became extremely advantageous in other areas & enhanced other senses required for survival.

The Tawny Owls in Finland were predominantly Grey but due to climate change & lowering temperatures they have gradually been turning brown. A study over 30 years has seen watched this change & scientists believe it’s due to the need to survive.

They found that during the harsher winters the brown owls were less abundant but as the winters have warmed the grey owls have become less abundant. Climate-driven natural selection has meant that the DNA coding in the genes is now favouring brown over grey.

The Algerian mouse has been studied intensively of late due to its ability to survive the common mouse poison warfarin.

Members of two species can’t generally mate &if they do the offspring either die young or sterile, but the Algerian mouse & the common house mouse have been mating & their offspring have been healthy & gone on to reproduce, & become super mice due to immunity to poison.

The peppered moth was light in colour before the industrial revolution, and dark examples were very rare.

Due to air pollution the lighter coloured moths were easily visible to predators. Once again Evolution stepped in & the moths over generations became dark to blend in with their surroundings, meaning that now the lighter coloured moth was hunted by predators more frequently.