1. Summary

 

MinuteEarth’s video, Are We Really 99% Chimp?, dove into the science behind evolutionary processes, DNA, and the reality behind the statement, “We are 99% chimpanzee”. They explained how scientists were only able to compare 2.4 billion letters in the DNA strands, leaving out 18% chimp DNA and 25% human DNA. Comparing this portion has allowed us to note that we are 98.77% the same as Chimps, but we have to remember that is a comparison without a combined 43% DNA.

Why Watch This Video?

Have you ever wondered how scientists were able to compare our DNA to that of a chimpanzee?

Would you like to understand why it is so difficult to compare DNA of 2 animals?

Have you ever been confused by the number of paired chromosomes?

Key Terms

DNA– the ‘strands’ that carry all our genetic information, present in all living things.

Genomes– a genome is an animal or person’s set of DNA, including each and every one of their genes.

Chromosomes– the paired threads that carry our genetic information and make up our genes.

Loose Ends

Chance Mutations

Early on in the video, they mention how “since we have split from our last common ancestor, chance mutations and natural selection have changed each of our genomes in radical and unique ways” (0:30). It turns out a chance mutation comes from the idea that, “all genetic mutations occur by ‘chance’ or at ‘random’ with respect to adaptation.” (Merlin, Francesca (2010) Evolutionary Chance Mutation: A Defense of the Modern Synthesis’ Consensus View.). Therefore, in the video they were basically saying that after we split from our common ancestor, both humans and chimpanzees have changed through genetic mutations as well as natural selection. This has allowed us to become separate and unique.

The Evolutionary Tree

Toward the end of the video, they mention being able to, “refine the evolutionary tree.” (02:30). The Evolutionary Tree, also known as The Phylogenetic Tree are hypothesized ideas about evolutionary relationships. These can be made for any species, not only humans and apes. (Khan Academy. (2017). Phylogenetic Trees.).

100% Great Ape?

As the video wraps up, it zooms in on the photo of the Phylogenetic Tree and states, “we are 100% great ape.” (02:40). In the simplest way possible, the branch of the Phylogenetic tree humans are on is called “Great Apes”, and is then split off into categories of, orangutan, gorilla, chimpanzee, and human ancestors! I added the photo below for a more visual reference.

Self-Test Questions

Scroll down for the answers.

1. How many chromosome pairs do humans and chimpanzees have, respectively?

1. 25, 24
2. 23, 25
3. 23, 24
4. 24, 23

2. While doing comparisons, scientists left out 25% of ________’s DNA.

1. Chimpanzee
2. Human
3. Neanderthal
4. Ape

3. While doing comparisons, scientists left out 18% of ________’s DNA.

1. Chimpanzee
2. Human
3. Neanderthal
4. Ape

4. Within the compared DNA, what exact percent of DNA do humans and chimpanzee’s share?

1. 99.99%
2. 99.77%
3. 98.99%
4. 98.77%

5. How many billion letters were able to be compared between humans and chimpanzees?

1. 2.0 billion
2. 2.2 billion
3. 2.4 billion
4. 2.6 billion

Answers

1. Answer C is correct, humans have 23 paired chromosomes, while chimpanzees have 24.

2. Answer B is correct, they left out a total of 25% of human DNA while doing their comparisons.

3. Answer A is correct, they left out a total of 18% of chimpanzee DNA while doing their comparisons.

4. Answer D is correct, humans are exactly 98.77% the same as chimpanzees in the DNA samples that were able to be compared.

5. Answer C is correct, 2.4 billion letters were able to be compared from both a human and chimpanzee.