Want to explore fun facts and the processes of evolution? Check out these sites:

OneZoom’s Tree of Life Explorer – An interactive map of the evolutionary links between all living things. Follow the branches, see which species are under threat, and be amazed by the diversity of life on earth.

The National Institute for Health (NIH) is a US government agency. One of its departments, the National Center for Biotechnology Information (NCBI) has collected reliable, scientifically vetted information about evolutionary biology. Explore the links!

The Phylogeny Explorer Project’s YouTube Series on the Systematic Classification of Life is a series of short videos. Watch the first one here, then go to the playlist for the rest.

Talk Origins is one of the best repositories of information on evolution available on the Internet. It explores the Evolution/Creationism controversy in depth.

Evolution is all about genes. Do you want to know more? Follow us to our page on genetics!

Genetics

How can we be related to apes?

• The human genome contains about 3 billion base pairs of nucleotides twisted into a single strand of DNA.
• A chromosome is a thread-like structure made up of DNA. Chromosomes are found in the nucleus of each cell.
• Humans have 23 chromosome pairs in each cell. Our closest non-human relatives, the great apes, have 24 pairs of chromosomes.
• The closest human relative, the great ape called the bonobo, has almost identical DNA sequences to that of human chromosome #2, but they are found in two separate chromosomes.
• About 6 million years ago, two separate chromosomes fused into one, resulting in the human chromosome #2. This genetic anomaly, repeated and passed down generation after generation, slowly changed our common ancestor’s descendants into the humans we are today. The other great apes, bonobos, chimpanzees, orangutans, and gorillas, have also changed since our common ancestor lived.

How different are we from our closest related species? Humans differ from each other in less than a tenth of one percent of our DNA. Human DNA differs from that of chimps and bonobos by only 1.2%. Humans, chimps, and bonobos are separated from gorillas by 1.6% of our DNA, and the DNA of all the African great apes – including humans – differ from orangutans by 3.1%.

How do genes work?

That’s a big question! In a nutshell, all living organisms, including humans, plants, fungi, bacteria, and viruses inherit genes from their parents when parental DNA recombines to form a spore, a seed, or an embryo. We get roughly half of our DNA from each parent, who got half of each of their parents’ DNA, who got half of each of their parents, and so on…you get the idea. Some genetic traits are recessive, meaning that we can pass those traits to our children even though we don’t exhibit that trait ourselves. Traits like eye and hair color, the shape of our noses and fingers, and whether we think cilantro tastes like soap or like deliciousness are examples of inherited traits.

But there’s something else about genes. Horizontal or lateral gene transfer happens when a foreign creature makes changes to our DNA, and that change gets passed to our offspring. For example, when a virus infects cells that make sperm and eggs, the virus’s DNA can become part of the genome of the offspring and can pass to future generations. When the same virus DNA shows up at the same spot on the chromosomes of different species, they are likely to share a common ancestor who passed that viral DNA to its offspring. About 5-8% of human DNA comes from viruses, and we share sixteen of these virus DNA sequences with all of the other great apes. The likelihood of these specific sixteen virus sequences showing up on the same spot on ape and human DNA just by chance is 1 in 2.057 x 10¹³⁸.  The virus DNA we share with apes is part of what proves that we share a common ancestor.