Biology Now, 2e

Neanderthal Sex ■ 313

Svante Pääbo is a Swedish geneticist who directs

the Department of Genetics at the Max Planck

Institute for Evolutionary Anthropology in Leipzig,

Germany. He specializes in using genetics to study

early humans and other ancient populations.

SVANTE PÄÄBO

mtDNA, Pääbo still thought there might be room

for some small contribution. Being a diligent

scientist, he decided to look even deeper—this

time at the whole Neanderthal genome.

Egg Sperm

Mom Dad

Mitochondrial DNA

Nuclear DNA

Nuclear DNA

Eggs provide nuclear DNA

and mitochondrial DNA to the

offspring cell. Mitochondrial-

DNA inheritance occurs only

from the egg.

Sperm provide only nuclear

DNA to the offspring cell.

Offspring cell

(zygote)

Figure 17.11

Mitochondrial DNA comes only from your mom (not from your dad)

In addition to the chromosomes in the nucleus (nuclear DNA), cells also have DNA in their mitochondria,

called mitochondrial DNA. Mitochondria and their resident DNA all come from Mom.

Q1: Why does mitochondrial DNA come only from your mother?

Q2: If a Neanderthal-human hybrid was born to a human mother and a Neanderthal father, could

you tell by mitochondrial-DNA sequencing?

Q3: If a Neanderthal-human hybrid was born to a human father and a Neanderthal mother, could

you tell by mitochondrial-DNA sequencing?

humans and other ancient populations, and he

has pioneered numerous techniques to extract

delicate DNA from even the tiniest slivers of

fossilized bones. At the time that he began his

work, it was easier to find and extract mitochon-

drial DNA because cells contain hundreds of

copies of this type of DNA, and only one copy of

nuclear DNA. In addition, mitochondrial DNA

can be isolated from cells and tissues that aren’t

so well preserved and from damaged DNA.

Whole-genome sequencing, by contrast, requires

well-preserved cells or tissues with fully intact

nuclear DNA. But despite his initial findings that

modern humans and Neanderthals did not share