Presentasi sedang didownload. Silahkan tunggu

# Population Genetics: Selection and mutation as mechanisms of evolution

## Presentasi berjudul: "Population Genetics: Selection and mutation as mechanisms of evolution"— Transcript presentasi:

Population Genetics: Selection and mutation as mechanisms of evolution
Population genetics: studi tentang Genetika Mendel di tingkat populasi Dalam Gen. Pop. Ada hukum Hardy Weinberg equilibrium (keseimbangan frekuensi gen HW)

Hardy-Weinberg Equilibrium
Frekuensi gen dan frekuensi genotipe akan stabil dari generasi ke generasi tanpa adanya seleksi, mutasi, migrasi dan genetic drift (penghanyutan genetik), non random mating

Random mating (kawin acak)
1. Tidak ada seleksi, migrasi, mutasi 2. Populasi besar 3. Frekwensi gen, genotipe tetap dari generasi ke generasi

5.10

Dapatkah seleksi mengubah frekuensi alel ?
Contoh : Dlm. Populasi terdpt. alleles B1 and B2 Frekuensi alel B1= 0.6 dan frekuensi B2 = 0.4. Bila terjadi kawin acak, maka frekeunsi genotipe tetap 0.36 B1B B1B B2B2

Can selection change allele frequencies?
Asumsi terdapat 100 individual 36 B1B B1B B2B2 Seleksi dilakukan. Asumsi semua B1B1 survive, 75% dari B1B2 survive dan 50% dari B2B2 survive.

Can selection change allele frequencies?
Population now 80 individuals: 36 B1B B1B2 8 B2B2 Allele frequencies now: B1 = (36 + ½ x 36)/80 = 0.675 B2 = (8 + ½ x 36)/80 = 0.325 Maka seleksi dapat mengubah frekeunsi alel.

Example 2 : N = 1000 ekor Jml belang hitam (Black = B) = 800
Jml. Belang merah (b) = 200 ekor Warna belang merah diseleksi 50 % (jadi survive 50 %) Maka : q1 = q 0 / (1 + S q 0 ) ; S = proporsi seleksi (yang di culling)

Nama : Syaifudin

Sickle Cell Anemia Sickle cell anemia is a condition common among West Africans (and African Americans of West African ancestry). In sickle cell anemia red blood cells are sickle shaped. Usually fatal by about age 10.

About 1% of West Africans have sickle
cell anemia. A single mutation that causes a valine amino acid to replace a glutamine in an alpha chain of the hemoglobin molecule. Mutation causes molecules to stick together.

Mengapa orang-orang dengan sickle
cell anemia dapat bertahan ?

Only individuals homozygous for
sickle cell gene get sickle cell anemia. Individuals with one copy of sickle cell gene (heterozygotes) get sickle cell trait (mild form of disease), but don’t get malaria.

Heterozygotes have higher survival than
either homozygote. Heterozygote advantage. Sickle cell homozygotes die of sickle cell anemia. “Normal” homozygotes more likely to die of malaria. Stabilizing selection for sickle cell allele.

Tiopik-topik Penyebaran/ distribusi golongan darah ABO pada populasi manusia di …… Penyebaran sickle cell anemia di dunia Pembentukan bangsa sapi Brahman (dari aspek bertanduk/tak bertanduk) Pembentukan bangsa sapi FH Hilangnya gen belangmerah pada populasi sapi perah di ….. Pewarisan gen penentu tipe jengger di populasi ayam di …..

7. Gen ketahanan genetik gterhadap parasit
8. Penyakit genetik pada ternak 9. Penyakiut lethal pada ternak 10. Ketahanan genetik terhadap penhyakit

Presentasi serupa

Iklan oleh Google