Video Transcript
Evolutionary biologists are
scientists that study how living things have evolved, changed, or gone extinct over
time. Which of the following best
explains why an evolutionary biologist might want to study the human genome? (A) To compare the human genome to
the genomes of other animals and determine how related we are to them. (B) To accurately predict how and
when the genes in the human genome will mutate. (C) To disprove the theory of
evolution by natural selection. Or (D) to create a genetically
engineered, more advanced human species.
Our question tells us that
evolutionary biologists study how organisms evolve and change over time. They also look at the evolutionary
relationships between different organisms, asking questions such as “How long ago
did various groups or taxa diverge from a common ancestor?” They may also investigate which
genes are conserved or mostly unchanged throughout the evolution of species.
One species that evolutionary
biologists may be particularly interested in is Homo sapiens. You likely already know that this
is the scientific binomial name for humans. Comparing the genome of humans to
the genomes of other organisms can reveal our evolutionary history. For example, genetic sequencing has
allowed us to establish that humans and chimpanzees have a higher degree of genetic
similarity than do humans and gorillas. This means that humans and
chimpanzees shared a common ancestor more recently than humans and gorillas or
chimpanzees and gorillas.
Many experiments in biology,
behavioral psychology, and other related fields cannot be conducted on humans for
ethical reasons. Instead, scientists use model
organisms, such as rats or monkeys, as the research subjects. When choosing model organisms, it
is important for the researchers to understand their evolutionary relationship to
humans.
Knowledge of the key genes that
have been conserved or changed is also critical when applying the results of these
types of studies. For instance, we know that research
conducted on a monkey would be more directly applicable to humans than research
conducted on rats because we have more genes in common with monkeys than we do with
rats.
Now, let’s return to our
question. The word “best” tells us that more
than one of the answer options could be correct. But we need to find the one that
most completely and accurately explains why an evolutionary biologist might want to
study the human genome. After reviewing the connection
between genetics, evolutionary relationships, and experimental design, we can see
that the correct answer is (A). An evolutionary biologist might
want to study the human genome to compare it to the genomes of other animals and
determine how related we are to them.