I had a science teacher, back at school, who, although he was a brilliant science teacher, wasn't to keen on biological evolution.

To be fair, back in the 1980's evolutionary sciences weren't what they are today, but I think his religious views may have also clouded his views a little so that he didn't delve much deeper.

He felt that biological evolution was a ball rolling itself uphill.

[img source](By Pnapora , CC BY-SA 3.0, Link)

In other words, he felt that species evolving naturally and becoming more complex without any external help violated the laws of thermodynamics... mainly that entropy and disorder are constantly increasing.

Entropy increasing is a well established fact. In this word of ours energy and other things follow the path of least resistance and as a result things tend to disorder or decay and become less complex over time.

Entropy tends to increase, not decreases.

At first glance it looks like species that are evolving and becoming more complex violate this fundamental principle.

There is a way however for entropy to decrease and for a system to become more complex. For this to occur the system needs to be an open system. Energy needs to be able to flow into and out of the system, work also need to be done within the system. Life makes use of many open systems, that all do work, they are all around us.

We can observe this in something we do everyday, when we eat.

By picking up an apple, chewing, swallowing and digesting it, we disorganize the apple. Or internal processes then extract the nutrients from the apple and discard the waste. Our bodies then use the extracted nutrients to build cells and fuel our activities.

Our bodies (the system) have taken in energy from outside (the apple) the system and used that energy to drive the work processes (digestion, metabolism). The metabolic process(work) has in turn increased the order (built cells etc.). To increase order you must also remove disorder (waste). This disorder (waste) is then removed from the system by going to the bathroom etc.

This also applies to biological evolution.

The planet earth is also not a closed system. It receives energy in the form of sunlight everyday, it radiates or looses energy in the form of heat that radiates out into space every night.

Life has many means of tapping into this energy flow. The organisms and species that are able to extract these resources most effectively are the ones that do best and ultimately survive. The competition between species for these resources is the work process and driving force behind the increasing order and complexity we see in biological evolution.

Basically the laws of thermodynamics are not broken, the energy required to roll the ball uphill, in this case, is supplied by sunlight and the work of rolling the ball is the competition between species.

Each living creatures daily struggle for survival pushed the ball slowly uphill and thereby increase complexity over eons of time.