Human Intervention in Evolution<br />
Advantages of Artificial Selection<br />Specific individuals selected to contribute to next generation for:<br />Economic ...
Reproductive Technologies<br />Artificial insemination<br />Multiple ovulations and embryo transfer (MOET)<br />Sex select...
Artificial Insemination<br />Semen is collected from male and transferred to females<br />Advantage is yield: normally in ...
Artificial Insemination<br />Advantages<br />Can fertilize many females<br />Can fertilize distant females<br />Can fertil...
Artificial Insemination in plants<br />Cover stigma<br />Remove stamen<br />Collect pollen from anthers<br />Expose to sti...
Artificial Insemination in plants<br />x<br />Rye<br />(Secale)<br />RR<br />Wheat<br />(Triticum)<br />WW<br />When one s...
Multiple ovulations and embryo transfer (MOET)<br />Valued females can also make a larger genetic contribution.<br />Injec...
Sex selection through sperm sorting<br />Add a harmless fluorescent dye to sperm<br />Dye attaches to DNA<br />X chromosom...
Oestrus synchronisation<br />All females in herd are effectively “put on the pill” by being given progesterone.<br />If al...
Cloning<br />Technique #1 – Embryo splitting<br />Pryor to blastocyst formation (>32 cells), the cells of the zygote can b...
Somatic cell fusion<br />Fusion with a donor embryo<br />
Dolly was created via nuclear transfer (somatic cell fusion)<br />
Some cloning successes<br />CC<br />Snuppy with the “mother” from which she was cloned<br />Snuppy with her surrogate moth...
The downside to cloning <br />Many unsuccessful attempts<br />CC (cat): 87<br />Snuppy (dog): 123<br />2nd Chance (bull): ...
Transferring genes<br />A gene transferred to bacteria is transformed<br />eg. human insulin grown in bacterial colony<br ...
Stem Cells<br />The source of the stem cell will determine how far-reaching its adaptive abilities are.<br />
Harvesting Stem Cells<br />Pluripotent stem cells are taken from the inner cell mass of a blastocyst.<br />Stem cells can ...
Therapeutic (non-reproductive) cloning<br />Embryos can also be cloned from the healthy cells of a diseased patient to cre...
Ethical Issues<br />Extraction of stem cells destroy what may have been a perfectly healthy embryo.<br />Current legislati...
Overcoming Infertility<br />Infertility problems are usually 50% female, 30-40% male and 10-20% incompatibility.<br />Solu...
Overcoming Infertility<br />IVF (In-vitro fertilisation)<br />Treats<br />Low sperm count<br />Poor swimmers<br />Damaged ...
In-vitro fertilisation<br />Egg incubated with sperm in culture fluid<br />Protective band of cells removed from around fe...
Overcoming Infertility<br />IVF with donor egg<br />Surrogacy<br />Implant IVF fertilised egg in to the womb of another fe...
In Conclusion<br />IVF ethical issues:<br />What happens to frozen egg, sperm or embryos after the death of one parent?<br...
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Ch. 16 Human intervention in evolution

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Ch. 16 Human intervention in evolution

  1. 1. Human Intervention in Evolution<br />
  2. 2. Advantages of Artificial Selection<br />Specific individuals selected to contribute to next generation for:<br />Economic reasons<br />Aesthetic reasons<br />
  3. 3. Reproductive Technologies<br />Artificial insemination<br />Multiple ovulations and embryo transfer (MOET)<br />Sex selection through sperm sorting<br />Oestrus synchronisation<br />
  4. 4. Artificial Insemination<br />Semen is collected from male and transferred to females<br />Advantage is yield: normally in a single mating there is the potential for one female to be inseminated<br />Via artificial insemination one ejaculate can fertilise 10 females. <br />Semen can be snap frozen in liquid nitrogen and stored for many years<br />
  5. 5. Artificial Insemination<br />Advantages<br />Can fertilize many females<br />Can fertilize distant females<br />Can fertilize beyond the lifespan of the male<br />Prized male can make larger genetic contribution<br />Disadvantages<br />Loss of genetic diversity<br />As one allele is favoured, alternatives are completely lost<br />Whilst breeding for a particular trait, others may be unintentionally gained or lost<br />
  6. 6. Artificial Insemination in plants<br />Cover stigma<br />Remove stamen<br />Collect pollen from anthers<br />Expose to stigma of many other plants<br />
  7. 7. Artificial Insemination in plants<br />x<br />Rye<br />(Secale)<br />RR<br />Wheat<br />(Triticum)<br />WW<br />When one species is used to fertilize another, a hybrid is produced<br />As chromosomes are non-homologous, hybrid is sterile<br />Treatment with certain chemicals will cause doubling of chromosomes in all cells, thereby producing a fertile hybrid<br />Sterile hybrid<br />WR<br />Treatment with colchicine<br />Fertile hybrid<br />(Triticosecale)<br />WWRR<br />
  8. 8. Multiple ovulations and embryo transfer (MOET)<br />Valued females can also make a larger genetic contribution.<br />Inject with FSH (stimulates super-ovulation)<br />Inject with GnRH (all eggs mature simultaneously)<br />Fertilise eggs through in-vitro fertilisation<br />Implant eggs in to surrogate female<br />MOET will usually increase the yield of a valued female by a factor of 7<br />
  9. 9. Sex selection through sperm sorting<br />Add a harmless fluorescent dye to sperm<br />Dye attaches to DNA<br />X chromosomes contain more DNA<br />Sperm containing X chromosome will fluoresce more brightly<br />Select these sperm<br />
  10. 10. Oestrus synchronisation<br />All females in herd are effectively “put on the pill” by being given progesterone.<br />If all are taken of progesterone at the same time, ovulation will occur simultaneously.<br />Makes herd easier to manage<br />
  11. 11. Cloning<br />Technique #1 – Embryo splitting<br />Pryor to blastocyst formation (>32 cells), the cells of the zygote can be divided with a very fine needle and implanted in to a surrogate.<br />Technique # 2 – Nuclear transfer<br />Can be performed via somatic cell fusion<br />Can be performed via fusion with a donor embryo cell<br />
  12. 12. Somatic cell fusion<br />Fusion with a donor embryo<br />
  13. 13. Dolly was created via nuclear transfer (somatic cell fusion)<br />
  14. 14. Some cloning successes<br />CC<br />Snuppy with the “mother” from which she was cloned<br />Snuppy with her surrogate mother<br />
  15. 15. The downside to cloning <br />Many unsuccessful attempts<br />CC (cat): 87<br />Snuppy (dog): 123<br />2nd Chance (bull): 189<br />Dolly (sheep): 277<br />This does not apply to plants as cloning occurs naturally<br />(cuttings, runners, rhizomes)<br />Shortening telomeres<br />Every time a cell divides it loses some DNA from its telomeres (ends of the chromosomes)<br />Implies that clones are born with “old” DNA<br />Recent studies have indicated that this may not be the case<br />Clones had loner telomeres than original<br />
  16. 16. Transferring genes<br />A gene transferred to bacteria is transformed<br />eg. human insulin grown in bacterial colony<br />A gene transferred to another species is transfected<br />eg. Spider gene in goat allows silk to be harvested from goat’s milk<br />Gene therapy involves the replacement of a faulty allele with a working one<br />
  17. 17. Stem Cells<br />The source of the stem cell will determine how far-reaching its adaptive abilities are.<br />
  18. 18. Harvesting Stem Cells<br />Pluripotent stem cells are taken from the inner cell mass of a blastocyst.<br />Stem cells can be used to replace damaged or diseased cells in almost any part of the body<br />
  19. 19. Therapeutic (non-reproductive) cloning<br />Embryos can also be cloned from the healthy cells of a diseased patient to create stem cells of the appropriate blood and tissue type.<br />
  20. 20. Ethical Issues<br />Extraction of stem cells destroy what may have been a perfectly healthy embryo.<br />Current legislation states that stem cells may only be taken from embryos deemed to be “in excess” during IVF procedures.<br />Embryos cannot be created simply for the purpose of harvesting stem cells<br />
  21. 21. Overcoming Infertility<br />Infertility problems are usually 50% female, 30-40% male and 10-20% incompatibility.<br />Solutions:<br />Donor Sperm<br />Legally the child belongs to the mother and her husband at the time of birth<br />
  22. 22. Overcoming Infertility<br />IVF (In-vitro fertilisation)<br />Treats<br />Low sperm count<br />Poor swimmers<br />Damaged fallopian tubes<br />Hostile mucous<br />Problems associated with implantation of egg in to uterine wall<br />
  23. 23. In-vitro fertilisation<br />Egg incubated with sperm in culture fluid<br />Protective band of cells removed from around fertilized egg<br />Embryo returned to mother’s uterus at either the 2 or 4 cell stage<br />
  24. 24. Overcoming Infertility<br />IVF with donor egg<br />Surrogacy<br />Implant IVF fertilised egg in to the womb of another female<br />GIFT (gamete intrafallopian transfer)<br />Sperm and eggs unable to meet can be collected and placed together in the fallopian tube<br />Intracytoplasmic sperm injection<br />Sperm unable to naturally penetrate egg are injected<br />
  25. 25. In Conclusion<br />IVF ethical issues:<br />What happens to frozen egg, sperm or embryos after the death of one parent?<br />On request of the family, can sperm / eggs be collected from someone after an untimely death?<br />Chapter review questions:<br />Ch. 16: 3-5,7,8,11<br />

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