sábado, 30 de noviembre de 2013

The man who bottled evolution

Evolution is a slow process that cannot be seen in real time. So evidences of evolution are always searched backward in time, using the fossil record, genetics or biochemistry of living things today, but it cannot be studied forward (we never know how species are going to change).


Plates with bacteria culture
In 1988, at the Michigan State University, an experiment started with bacteria. Richard Lenski and his research group began to grow 12 populations of Escherichia coli and by reproducing and caring them day and night they have completed over 58.000 generations(equivalent to 1 million years in humans).
The conclusion in this experiment, which has been operating for over 25 years, is evolution never stops, even when the conditions of life do not change.

I leave several links to the news

Experiment data.  Science

References: Fogonazos

martes, 26 de noviembre de 2013

Darwin on the evolution trail

This video summarizes Darwin's life, from his early youth as a collector of insects through the 5 years trip on the HMS Beagle until he published his book "On the origin of species by means of Natural Selection". We can see how he was shaping and maturing his shocking and revolutionary idea of evolution and the difficulties he encountered .... even in his own wife ("I don't like your ideas, Charles!")



Reference: Evolution of life
 

miércoles, 9 de octubre de 2013

Scientific method

The scientific method is the way to work in Science, to investigate, to acquire new knowledge or to correct the previous ones. It is the way of working in science. It is simple but sistematic, useful and efficient to get results from investigation phenomena.
This song describes step by step the scientific method:
  • Observation 
  • Ask a question 
  • Hypothesis 
  • Test or experimentation 
  • Analize data 
  • Conclusion

jueves, 23 de mayo de 2013

Periodic Table Song

Here you are a funny video about the elements of the Periodic Table. Although the elements are listed in order of atomic number in stead of groups or periods I'm sure that it will be usefull to learn and review about this unit. I hope you enjoy it as much as me.


martes, 12 de marzo de 2013

Pediodic table contest


As you know we have changed the subject in Science and we are now studying units about Chemistry. So I suggest that our new theme should be The Periodic Table. 
You have the information about the Periodic Table contest by clicking here

domingo, 10 de marzo de 2013

Chemical reactions

In this video you can see reactions between alkali metals and water.  Pay attention to the narrator and try to follow the explanations.  Don't use subtitles, they are wrong.

Obviously it is NOT recommended to do this at home.

miércoles, 20 de febrero de 2013

Reproduction

Reproduction is the process that continues life on Earth.Take a look in these couple of videos about the female reproductive system.   Watch them carefully to learn and understand the menstrual cycle, ovulation and egg release, hormones, changes, etc


martes, 5 de febrero de 2013

Health and illness

There are a new couple of lessons from Skoool in order to know several concepts about health. 



Learn about micro-organisms and different types of microbes by clicking on this link:  Micro-organisms

Learn about immunity and how vaccines can be used to help the body fight against infections:  Vaccines and immunity

martes, 15 de enero de 2013

lunes, 14 de enero de 2013

Nervous system: Synapse

In these couple of videos you can learn about neurons exchange information through a synapse. Try to understand how it works.