Lecture 4 Flashcards
who was a big critic of darwin
Richard Owen
Much attention was paid to the implications for human origins, a topic Darwin was initially reluctant to address directly– why didn’t he address it directly
remember, he was still religious, so he didn’t want to go against everything about god and religion… so he sat back and allowed other to argue for him basically
Darwin defended his work largely through surrogates
what were some critiques of darwins theory
Critiques from the scientific community focused on Darwin’s inability to explain how traits are inherited
why is Genetics important to the study of human origins
Genetics is important to the study of human origins because it addresses the withering criticism Darwin was largely unable to counter in his day
What Didn’t Darwin Know
- What is the source of individual variation?
2. How are characteristics inherited?
What is the source of individual variation?
genes
How are characteristics inherited?
Particulate Inheritance
what is Blending inheritance
was the vaguely-‐defined, yet widespread belief that traits from a mother and a father are ‘mixed’ like liquids
From Classical Greek times to the late 19th century, the concept was the only means of explaining inherited traits
what was a limit of blending inheritance
Blending inheritance could not account for outliers exhibiting traits beyond the limits of, or not found in, the two parents
what are gemmules
All cells in the body are infused with part-‐specific particles that determine physical traits called gemmules
can gemmules be altered
Importantly, gemmules can be altered over the course of an individual’s lifetime
what is Pangenesis
darwin’s theory of how blended inheritance worked
Pangenesis basically provided a blueprint for what
Lamarckian inheritance
how did Pangenesis work
All cells in the body are infused with part-‐specific particles that determine physical traits called gemmules.
Importantly, gemmules can be altered over the course of an individual’s lifetime
Gemmules migrate from their home cells and are collected in the reproductive organs
Parent gemmules are then traded through sexual reproduction
did Pangenesis support or go against natural selection
Ultimately, Pangenesis undermined natural selection because it incorporated into it a competing theory of development of new traits
There are two types of cells, and two ways in which cells divide, what are the ways
somatic cells
germ cells
how do somatic cells work and wha are they
- somatic cells, which compose the body (liver cells, lung cells, skin cells, bone cells, etc.), divide in a clonal process called mitosis, in which the cell material doubles within the cell forcing it to split in two. The result is two identical diploid cells
how do germ cells work and what are they
- germ cells, which are found in the reproductive organs/ systems, divide into 4 haploid cells, which have half the genetic information of a somatic cell. This process is called meiosis
what is mitosis
mitosis is cell division through a cloning process,
what is meiosis
is associated with gametes and there is a splitting of the chromosomes
what are in Chromosomes
Hold DNA
Contains hundreds to thousands of genes
what is Locus
specific location of a gene