07 - Lion Family Reunion: Conservation Biology Genetics
Background Information Excerpts from EDVO-Kit 920 A cell’s DNA contains a wealth of valuable information. This molecule is made of long chains of four nucleotides and is often called life’s “instruction manual” because it allows organisms to create the proteins needed to grow and live. DNA’s structure also allows this essential information to be passed down from mother to daughter cells and from parents to offspring. Locked within these sequences of nucleotides is also the story of how DNA itself has changed over multiple generations. Evolutionary biologists and molecular ecologists study these patterns of change to reconstruct the past. For example, by analyzing DNA changes scientists have been able to reconstruct how life evolved on Earth and the evolutionary relationships between different species. Phylogeographers, scientists who specialize in the intersection of evolution, ecology, and biogeography, have similarly analyzed DNA changes to discover the migration routes of our own ancestors and how ancient communities responded to past ice ages. How do phylogeographers make the leap from DNA sequences to a species history? How do species histories help us solve current-day problems? And what does this all have to do with two orphaned lion cubs? Read on to discover. PHYLOGEOGRAPHY – WHEN MAPS AND TREES COMBINE In phylogeography, information about differences in the DNA of individuals (i.e. a species’ genetic varia - tion), the geographic distribution of this variation, and the evolutionary relationships between different DNA sequences are analyzed together in order to detect genetic signals of past events. Phylogeography studies are diverse – some involve tens of thousands of sampled individuals and look at DNA changes
1. COLLECT DNA SAMPLES
AAATGAGTCC 2. READ THE DNA
AAGTAAGTCC
AAGTCAGTGC
3. IDENTIFY REGIONS THAT VARY
AAGTAAGTCC
AAGTCAGTGC
AAATGAGTCC
4. COMBINE REGIONS INTO HAPLOTYPES
G+C+G=Haplotype A, A+G+C=Haplotype B, G+A+C=Haplotype C 5. GIVE INDIVIDUALS A HAPLOTYPE
Haplotype A
Haplotype B
Haplotype C
6. LINK TO A LOCATION AND GROUP INTO POPULATIONS
Figure 1: Key steps in a phylogeography study. 7. MAKE A GENETIC MAP 8. MAKE A GENETIC TREE
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