Cold blooded, hot blooded (I).

I still remember the day Jurassic Park premiered. What a great movie.

And of all the scenes, I especially remember the one where they first saw different families of dinosaurs around a lake, cooling off and drinking.

One of the paleontologists, recovering after the first impression, said while observing an immense brachiosaurus:

Cold blooded, hot blooded (I)

“You have to rule out the cold-blooded theory, we were wrong, it’s a warm-blooded creature!”

Logically, I did not pay the slightest attention to the comment, since I was entertained watching the gigantic animal that appeared on the screen. But seeing the film for the fourth or fifth time, the question was forced: What is a cold blooded animal?

Cold blooded, hot blooded (I)

If we let ourselves be carried away by the logical noun-adjective relationship, we would think of animals that have a high or low blood temperature. But the shots do not go there.

It has always been said that an animal of hot blood is the one who keeps his relatively constant body temperature no matter how much the ambient temperature varies.

Cold blooded, hot blooded (I)

The human being is within this group, since as we all know, we have a temperature close to 37º C. Our body always tries to maintain this temperature because it is optimal for our cells to work, and therefore for our survival.

Instead, the animals cold blood had always been grouped as those who change their internal temperature based on environmental conditions, leaving aside any internal controls.

Cold blooded, hot blooded (I)

Within this group we could find the lizards. Some of these animals, unable to control their internal temperature, need to accumulate heat during the hours of sunlight to maintain it in the coldest hours.

The problem appears, as always, by our own definition.

Defining all animals into two large groups is simplifying a great complexity of living beings to the maximum, so over time, it was observed that cold-blooded and warm-blooded did not serve to classify a large number of animals.

Cold blooded, hot blooded (I)

For this reason, what were two very defined groups, became limits.

At one extreme, animals with great control of their internal temperature. In the other, those who are unable to perform any internal control, so they are totally dependent on the external environment.

What was “hot blood” came to be distributed into three large groups:

Cold blooded, hot blooded (I)
  • endothermy
  • Homeothermy.
  • Tachymetabolism.

And what was understood as “cold blood”, began to separate into the following:

  • ectothermy.
  • Poikilothermia.
  • Bradymetabolism.

Now the limits are not so simple, right?

In the next entry, we will explain the different groups of regulation of what is known as hot blood.

In the meantime, stay warm.

Cold blooded, hot blooded (I)

More information | The Reptipage In Genciencia | The ideal temperature to live longer