One has to devote oneself to a particular pursuit. To be successful at anything, you have to make a total commitment to it.

There have been some friendships lost over this. That's the most difficult for me. I find it very uncomfortable to know that I was at one time close friends with someone, and because of jealousies and misunderstandings and so on, these friendships have dissolved.

My real father died when I was two years old, so I never knew him. He was a barber in Chicago.

In our case, finding a Lucy is unique. No one will ever find another Lucy. You can't order one from a biological supply house. It's a unique discovery, a unique specimen.

I was aware of it, but I grew up in a very a-religious family. My mother never went to church, she never had any religious training or background. It was never a part of our social interaction.

When I realized, in 1978, that Lucy did represent a new species of human ancestor, and that I had an opportunity to name this new species, I realized this was a revolutionary step in understanding human origins.

I was very intellectually oriented, very early on.

One has to devote oneself to a particular pursuit. To be successful at anything, you have to make a total commitment to it.

But it really wasn't until three to four years later, when we had an opportunity in the lab to make very detailed observations, and comparisons with other fossil discoveries, that we realized she was a new species of human ancestor.

And what I wanted to do was, I wanted to explore problems and areas where we didn't have answers. In fact, where we didn't even know the right questions to ask.

As an undergraduate, I had an opportunity to go on a number of archeological digs. So I had experience excavating, digging up remains of ancient Indian villages in the Midwest and in the Southwest.

When the first fossils began to be found in eastern Africa, in the late 1950s, I thought, what a wonderful marriage this was, biology and anthropology. I was around 16 years old when I made this particular choice of academic pursuit.

Most achievers I know are people who have made a strong and deep dedication to pursuing a particular goal. That dedication took a tremendous amount of effort.

I realized immediately that this was a terribly important discovery, but I didn't realize how important it would be until we had spent a lot of time in the laboratory studying it.

Normally, we are happy to find a fragment of jaw, a few isolated teeth, a bit of an arm, a bit of a skull. But to find associated body parts is extremely rare.

I think that many of my ideas are correct, but I'll bet you, before my death other discoveries will be made that will prompt me to alter various ideas I have about human evolution.

But what really excited me was the idea that humans had a tremendous pre-history that went back millions of years. I wanted to go to Africa to find some of these creatures.

Lucy brought with her an image of our human ancestors that you don't get when you find a jaw or an arm bone or a leg bone. Here was 40 percent of a single skeleton.

Scientists are very afraid of being proven wrong.

This was the most important discovery I had ever made in my life. It was a discovery which has irrevocably changed my whole life's direction. It immediately elevated me to the status of one of the world's leading anthropologists.

Commitment, belief and positive attitude are all important if you're going to be a success, whether you're in sports, in business or, as in my case, anthropology.

Evolution explains our biological evolution, but human beings are very unique creatures. As the Dobzhansky said, all animals are unique; humans are the uniquest. And that uniqueness of being human, language, art, culture, our dependency on culture for survival, comes from the combination of traditional biological evolution.

I don't think we interbred with the Neanderthals at all. There are some people who think that there was some level of interbreeding. I think that we look so biologically different, that we looked and we acted so different, and we culturally were so different that we would not have had interbreeding between two species.

We are placed in the genus of Homo, which is Latin for man - Homo sapiens: supposedly wise men. I sometimes think - wonder - whether we really are wise men.

What makes us human depends on what place on our evolutionary path we're talking about. If you go back six million years ago, what makes us human is that we were walking upright. That's all. If you go to 2.6 million years ago, it's the fact that we're designing and making stone tools.

What's changed is we now have good anatomical, geological, archaeological evidence that Neanderthals are not our ancestors. When I wrote 'Lucy,' I considered Neanderthals ancestors of modern humans. We have gone back twice the age of Lucy, six million years. And we see that upright bipedal walking goes back that far in time.

Where we are going as a species is a big question. Human evolution certainly hasn't stopped. Every time individuals produce a new zygote, there's a reshuffling and recombination of genes. And we don't know where all of that is going to take us.

One has to take initiative in life to achieve what he or she wants.

Productivity is never an accident. It is always the result of a commitment to excellence, intelligent planning, and focused effort.

Above all else, we need a reaffirmation of political commitment at the highest levels to reducing the dangers that arise both from existing nuclear weapons and from further proliferation.

It's true that the war in Iraq opened a distance in relations between part of Europe and the U.S. government, but our basic ties are stronger than that. We share democracy, free markets and a commitment to Western security. We differ on how to guarantee that security.

A great deal has been said about my commitment not to raise taxes. It's a core value - it's common sense - it's important to keeping and growing jobs - and it's mainstream!

And because of these programs like Medicare, Medicare prescription drugs, Social Security, we now have the healthiest and wealthiest group of senior citizens that the world has ever seen. This is a continuing commitment to that.

You need the words, you need the script, you need the material, you need the commitment, you need the passion, it's like we depend on writers, we depend on producers, directors depend on us and once things are in the divine order as they happen.

My satisfaction comes from my commitment to advancing a better world.

You may count on Mexico's support, since your commitment to the noblest causes of mankind and your vast experience are and will be invaluable in enabling us, together, to achieve a better world.

The Election Assistance Commission represents a major, unprecedented commitment from the federal government to sustained freedom and vibrant democracy. I am humbled by the prospect of being one its charter members.

We have a close, unshakable bond between the United States and Israel, and between the American and Israeli people. We share common values and a commitment to a democratic future for the world, and we are both committed to a two-state solution. But that doesn't mean that we're going to agree.

To work with a director that has emotional commitment and passion toward the characters, and the piece, and the experiences, it only enriches your work.

Unless commitment is made, there are only promises and hopes... but no plans.

I'm not just a politician, I'm a guy who has a real deep, substantive, commitment to education.

My commitment to Atlanta and passion for sports and competition make this acquisition a perfect fit for me.

We must have a relentless commitment to producing a meaningful, comprehensive energy package aimed at conservation, alleviating the burden of energy prices on consumers, decreasing our country's dependency on foreign oil, and increasing electricity grid reliability.

Commitment and co-operation to overcome barriers and difficulties, and determination to achieve the standards of the EU as well as NATO membership, are and have always been the principal target.

One of the best kept secrets in America is that people are aching to make a commitment, if they only had the freedom and environment in which to do so.

For those who have made the ultimate sacrifice, we are grateful that such men and women were among us. For those who continue to serve, we honor their commitment. For those who return to civilian life, we honor their service.

You need to make a commitment, and once you make it, then life will give you some answers.

There's a higher form of happiness in commitment. I'm counting on it.

Our children's health and well-being are dependent on our commitment to promoting food access and good eating habits at home, at school and in the community.