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Mabibi au mabwana (sex depends on temparature)

Date post: 05-Jul-2015
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I am working at KWS (Kenya Wildlife Service) in Malindi, as a volunteer of JICA. My job is teacher of environment. This presentation is about how creatures control sex ratio in nature. Also introduced new theory about how dinosaurs extinct related to control sex ratio. Also Introduced about some creatures adapted to cloning.
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Mabibi? au Mabwana? Takatoshi AKAI KWS Malindi Marine Park JICA/JOCV231
Transcript
Page 1: Mabibi au mabwana (sex depends on temparature)

Mabibi? au Mabwana?

Takatoshi AKAI

KWS Malindi Marine Park

JICA/JOCV231

Page 2: Mabibi au mabwana (sex depends on temparature)

Outline

• Temperature decide sex in nature 1

• Temperature decide sex in nature 2

• How dinosaurs extinct?

• The case of mammals

• Male? Or Female?

• Clone

Page 3: Mabibi au mabwana (sex depends on temparature)

Temperature decide sex in nature 1

In the full moon on the beach.

Page 4: Mabibi au mabwana (sex depends on temparature)

① At full moon, the sea become high tide ② Sea water can not reach higher than high tide, so eggs will not wash away

Page 5: Mabibi au mabwana (sex depends on temparature)

At first, when eggs lay,

they are neither male nor female.

The eggs hatch only when the temperature of sand between 26℃~ 34℃

Page 6: Mabibi au mabwana (sex depends on temparature)

• Therefore, because of global warming.

The number of female turtles are increasing.

Page 7: Mabibi au mabwana (sex depends on temparature)

Temperature decide sex in nature 2

Page 8: Mabibi au mabwana (sex depends on temparature)

①In reverse, crocodile lay eggs

in many different places. ②Also, temperature effected in reverse.

Therefore, crocodile can control number of female and male!!

Page 9: Mabibi au mabwana (sex depends on temparature)

Case Study: Louisiana dismal

② ③

Page 10: Mabibi au mabwana (sex depends on temparature)

①Beside the river (Dry & Warm)

Beside the river, there are dried and warm enough.The temperature close to 34℃

Page 11: Mabibi au mabwana (sex depends on temparature)

②Moisture swamp

Moisture swamp,

there are humid and colder.

The temperature close to 26℃

Page 12: Mabibi au mabwana (sex depends on temparature)

③Water side in halfway point

• In halfway point, humid a bit, not so warm, not so cold

Page 13: Mabibi au mabwana (sex depends on temparature)

How dinosaurs extinct?

Page 14: Mabibi au mabwana (sex depends on temparature)

Maybe…

Continental drift theory: 1 big continent “Pangaea” break up and connected continuously. It lead volcano and shut sunlight.

Huge Meteor Theory:Huge meteor hit the earth and extinct

Page 15: Mabibi au mabwana (sex depends on temparature)

New TheoryDinosaur is close to reptile, like crocodile.

Because temperature changed to cold at that time, then all of their eggs became female.

Then, species could not continue to raise their off springs.

Page 16: Mabibi au mabwana (sex depends on temparature)

No. of species

Page 17: Mabibi au mabwana (sex depends on temparature)

The case of mammals and birds• If X chromosome is only 1, who will become male.• If X chromosome is 2, who will become

female

Page 18: Mabibi au mabwana (sex depends on temparature)

Male? Or Female?

Page 19: Mabibi au mabwana (sex depends on temparature)

Asexual reproduction = Clone

• “Cnemidophorus”, kind of lizard habitat in South-west in US.

• They are only female.

• Reproduce own self,

without sex.

Page 20: Mabibi au mabwana (sex depends on temparature)

• Aphidoidea also reproduce

oneself by cloning without sex.

Female clone herself inside of her and lay eggs.

Male will born from cloned eggs, and sex with female to lay eggs.Those eggs will hatch in spring, but all of them are female.

Page 21: Mabibi au mabwana (sex depends on temparature)

In conclusion

• Some reptile species depends on temperature to control their sex ratio.

• Mammals depends on X chromosome to decide sex ratio.

• Some species choose cloning to make offspring.

• Some are use cloning and sex, depends on the season.


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